Retractor cannula system for accessing and visualizing spine and related methods

ABSTRACT

Retractor cannula systems may be used for accessing and visualizing the spine and related methods of treatment, including a forward-looking retractor cannula system for creating a working space and the retractor cannula system having atraumatic dissection capability to allow visualization in spine. The devices and methods described may be used, for example, to perform annulus repair, herniated disc excision, and denervation of neurological tissue; to dispense pharmacological agents and/or cell or tissue therapy agents; to diagnose disc degeneration and bony degeneration, spinal stenosis, and nucleus decompression, and to perform disc augmentation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Application No. 61/106,914, filed Oct. 20, 2008, thedisclosure of which is hereby incorporated by reference in its entirety.This application is also related to U.S. application Ser. No.12/199,706, filed Aug. 27, 2008, which is also hereby incorporated byreference in its entirety.

BACKGROUND

Injured intervertebral discs are generally treated with bed rest,physical therapy, modified activities, and pain medications forsubstantial treatment durations. There are also a number of treatmentsthat attempt to repair injured intervertebral discs and to avoidsurgical removal of injured discs. For example, disc decompression is aprocedure used to remove or shrink the nucleus, thereby decompressingand decreasing the pressure on the annulus and nerves. Less invasiveprocedures, such as microlumbar discectomy and automated percutaneouslumbar discectomy, remove the nucleus pulposus of a vertebral disc byaspiration through a needle laterally inserted into the annulus. Anotherprocedure involves implanting a disc augmentation device in order totreat, delay, or prevent disc degeneration. Augmentation refers to both(1) annulus augmentation, which includes repair of a herniated disc,support of a damaged annulus, and closure of an annular tear, and (2)nucleus augmentation, which includes adding or removing material to thenucleus. Many conventional treatment devices and techniques, includingopen surgical approaches, involve muscle dissection or percutaneousprocedures to pierce a portion of the disc under fluoroscopic guidance,but without direct visualization. Several treatments also attempt toreduce discogenic pain by injecting medicaments or by lysing adhesionsin the suspected injury area. However, these devices also provide littlein the form of tactile sensation for the surgeon or allow the surgeon toatraumatically manipulate surrounding tissue. In general, theseconventional systems rely on external visualization for the approach tothe disc and thus lack any sort of real time, on-board visualizationcapabilities.

Accurately diagnosing back pain is often more challenging than expectedand often involves a combination of a thorough patient history andphysical examination, as well as a number of diagnostic tests. A majorproblem is the complexity of the various components of the spine, aswell as the broad range of physical symptoms experienced by individualpatients. In addition, the epidural space contains various elements suchas fat, connective tissue, lymphatics, arteries, veins, blood, andspinal nerve roots. These anatomical elements make it difficult to treator diagnose conditions within the epidural area because they tend tocollapse around any instrument or device inserted therein. This mayreduce visibility in the epidural space, and may cause inadvertentdamage to nerve roots during device insertion. Also, the insertion of avisualization device may result in blocked or reduced viewingcapabilities. As such, many anatomical elements within the epiduralspace may limit the insertion, movement, and viewing capabilities of anyaccess, visualization, diagnostic, or therapeutic device inserted intothe epidural space.

BRIEF SUMMARY

Some embodiments herein relate to cannula retractor systems foraccessing and visualizing the spine and related methods of treatment. Insome examples, the retractor assembly may be used to create a workingspace and/or having an atraumatic configuration that may be used todisplace or dissect tissue. In some further examples, the retractorassembly may comprise a set of movable elements or jaws about the distalend of a cannula which may be opened to create a larger visualizationfield and working space. Endoscopes and various therapeutic toolslocated in the cannula may be used as the jaws are kept open, or in someinstances, when the jaws are in a closed position. The devices andmethods described herein may be used, for example, to perform annulusrepair, herniated disc excision, denervation of neurological tissue, orthe removal of bony material from the spine. The devices and methods mayalso be used to deliver pharmacological agents and/or cell or tissuetherapy agents, to diagnose disc degeneration and bony degeneration, totreat spinal stenosis, and to perform nucleus decompression, or discaugmentation.

In one embodiment, a retractor cannula device may comprise a tubularbody with a retractor assembly located at the distal end of the tubularbody. The tubular body may have at least one lumen configured to hold anendoscopic or other visualizing system, and the retractor assembly maycomprise a first closed configuration and a second open configuration.In some embodiments, the at least one lumen may be configured toremovably receive the endoscopic system. The retractor cannula devicemay also comprise an endoscopic system. In one embodiment, the retractorassembly comprises at least one movable element, where the at least onemovable element has a curved surface. The curved surface of the at leastone movable element may comprise a first point having a first tangentand a second point having a second tangent that is perpendicular to thefirst tangent. In some embodiments, the curved surface of each of themovable elements may be uniformly oriented around a longitudinal axis ofthe retractor cannula device to generally form a rounded tip in thefirst closed configuration. In other embodiments, the curved surface ofeach of the movable elements may be non-uniformly oriented around alongitudinal axis of the retractor cannula device to form a tapered tipin the first closed configuration. In some embodiments, the tapered tipcomprises a linear taper region. In certain embodiments, the curvedsurface of at least one movable element is non-uniformly andasymmetrically oriented around a longitudinal axis of the retractorcannula device to form an angled tip. In some embodiments, the angledtip may be oriented across a longitudinal midline of the retractorassembly. In some embodiments, the at least one movable element maycomprise an optically transparent material. Some embodiments of aretractor assembly may comprise at least two movable elements.

In some embodiments of a retractor cannula device, the cross-section ofthe retractor assembly perpendicular to a longitudinal axis of thedevice may comprise a non-circular configuration. In some embodiments,the cross-section of the retractor assembly perpendicular to alongitudinal axis of the device may comprise at least one linear region.In some embodiments of a retractor assembly comprising at least onemovable element, the at least one movable element may comprise a convexouter surface. In some embodiments, the at least one movable element maycomprise a concave inner surface.

In some embodiments of a retractor cannula device, the retractorassembly may comprise at least one movable element and at least onefixed element, where the movable and the fixed element(s) may comprisean optically transparent material. In one embodiment, when the retractorassembly is in the first closed configuration, the at least one movableelement and the at least one fixed element may form a side aperture. Insome embodiments, the at least one fixed element is distal to thetubular body and may be oriented parallel to a longitudinal axis of thedevice.

Some embodiments of a retractor cannula device may further comprise ahandle at the proximal end of the tubular body. The handle may comprisea pivot member and a device-locking member. In some embodiments, thehandle may further comprise a pivot member lock configured to restrictthe movement of the pivot member. Some embodiments of a handle may alsocomprise resistance mechanisms to set the actuation force of the pivotmember. In some embodiments, the device-locking mechanism may beconfigured to secure an endoscopic system. Some embodiments of a handlemay comprise one or more ports. Some embodiments of a handle mayadditionally or alternatively comprise one or more lumens. In oneembodiment, the at least one port may be configured as a flush port,and/or at least one more port may be a visualization port incommunication with the at least one lumen configured to hold anendoscopic system.

In one embodiment, a method of accessing a portion of the spineincluding percutaneously approaching a portion of the spine with aninstrument having direct visualization capability, providing an accessto a portion of the spine using the instrument, and positioning a deviceabout the portion of the spine using the instrument. In a furtherembodiment, the instrument may comprise a retractor assembly and themethod may include passing the retractor assembly in a closedconfiguration to a spine region, and actuating the retractor assembly toan open configuration. In another embodiment, the retractor assembly maycomprise a material or marker to augment visualization of the structureby imaging modalities used inside or outside of the body. A diagnosticdevice, a therapy delivery device, a stimulation device or apharmacological therapy device may be also inserted into the instrumentand to the spine region. In another embodiment, the method includesimplanting a device using the direct visualization capability of theinstrument. In still other embodiments, a method includes providingaccess to a portion of the spine, such as the spinal epidural space, theannulus, the layers of annulus, the disc nucleus, the facet joints, theforamen, or the spine musculature. In still another embodiment, themethod also includes receiving visualization information from an imagingmodality located outside of the body such as fluoroscopy, magneticresonance imaging, and/or computer tomography. In still otherembodiments, the method includes using the direct visualizationcapability of the instrument to maneuver the instrument between a spinalnerve root, the spinal dura and nerve tissue and other tissues, and/oratraumatically manipulating the spinal nerve root or other soft tissue.In yet another embodiment, the method includes using the instrument todeliver disc augmentation devices, nucleus augmentation devices or discexcision devices. In another embodiment, the instrument may be used fordiagnostic purposes.

In one embodiment, a retractor cannula system may comprise at least twointerlocking jaws that have a substantially rounded or curved geometrywhen in the closed configuration. Following positioning of the retractorcannula system about the target site, the jaws of the retractor assemblymay be placed in the open configuration and may be used as an atraumatictool for dissection and/or a displacing tissue to create working space,thereby enhancing visualization of other surrounding structures. In oneembodiment, the retractor assembly is a forward-looking structure sothat the distal tip of the retractor assembly may push obstructivetissue away from the scope, and the distal tip of the retractor assemblymay provide a depth of view between the scope and the targeted sites tobe treated.

One embodiment is directed to a retractor cannula device comprising amulti-lumen elongate shaft, a retractor assembly attached at its distalend of the shaft, wherein the retractor assembly comprises at least twojaws that are pivotably coupled to the distal section of the elongateshaft, capable of a first closed configuration and a second openconfiguration, wherein the second open configuration may displacetissue, expand the visual field, and/or maintain a working field. In oneembodiment, the jaws of the retractor assembly form a rounded shape ortapered shape tip when in the closed configuration. In otherembodiments, the retractor assembly may have any of a variety of othershapes, tapered or not. In certain embodiments, the jaws may be made ofan optically opaque material or an optically transparent material. Insome examples, an endoscope or fiber optic line within the elongateshaft with an optically transparent retractor assembly may be usedvisualize the surrounding tissue when the jaws are in either the openand closed configuration.

Some embodiments may also comprise a retractor assembly catheter havinga proximal portion and a distal portion and one or more lumens, whereinsaid proximal portion contains 3 separate lumens, one of said lumensbeing suitable for allowing the passage of an endoscope, one of saidlumens being suitable for aspiration and/or irrigation, and the otherlumen being suitable for allowing passage of therapeutic instruments orinfusion of medications. In other embodiments, the inner edge of thejaws may be hinged to allow an angle to be formed in the openconfiguration, the angle being anywhere from about 1 degree to about 359degrees. In certain embodiments, the hinge may be a rivet or screwaround which the jaws rotate, and in certain embodiments, the hinge maybe a living hinge involving the flexion of a pliable material.

In another embodiment, an apparatus and method for treating spinaldisorders is provided, which comprises introducing a retractor cannuladevice having direct visualization capability into a patient, steeringthe retractor cannula device to a position about the spinal targetedsite using visualization information provided by an endoscope or othervisualization device in combination with the retractor cannula device,dissecting and/or displacing tissue with the retractor assembly of theretractor cannula device to create a working space, and using theretractor cannula device to provide a disc augmentation device in theworking space for treating disc degeneration.

In another embodiment, a method for treating intervertebral discdegeneration in a spine of a body includes making an incision into askin of the body, introducing a retractor cannula device that permitsdirect visualization into a portion of the spine, introducing a therapydevice into retractor cannula device, and treating the discdegeneration.

In another embodiment, a method for treating intervertebral discdegeneration includes introducing a retractor cannula device thatpermits direct visualization capability into a portion of the spine,steering the retractor cannula device to a position adjacent to a discor neural tissue using visualization information provided by avisualization system, displacing the neural tissue or other tissues withthe retractor cannula device to create a working area, using theretractor cannula device to deliver a therapy device for treatingintervertebral disc degeneration, and treating the disc degeneration.The visualization system may be used in conjunction with the retractorcannula device or may be integrated with the retractor cannula device.In some embodiments, the therapy device is a nucleus decompressiondevice configured to inject substances and/or remove material from thenucleus, the annulus, or one or more fragmented segments of thevertebral disc. In some embodiments, a therapy device may be used toshrink a portion of the nucleus or the annulus. Treating the discdegeneration may also comprise repairing a herniated disc, supporting adamaged annulus, adding or removing material with respect to thenucleus, annulus or a bony structure, and/or sealing an annulus. In oneembodiment, displacing the tissues comprises actuating the retractorstructure of the retractor cannula device to an open or widerconfiguration.

In another embodiment, a system for intervertebral disc augmentationincludes a retractor cannula device configured to provide access for adisc augmentation device to an intervertebral disc. In one embodiment,the retractor cannula device includes an elongate body, one or moremovable jaws, a direct visualization device, and at least one workingchannel. The jaws may be coupled to the elongate body in any suitablehinge configuration or other articulation, and is configured to at leasttransition from a closed to and open configuration. In one or more ofthe embodiments, the jaws may be configured to displace tissues in thespinal area, and to create a working area. A direct visualization deviceinserted into the retractor cannula device or may be integral with theretractor cannula device, using a fiber optic line or an imaging sensorlocated on the direct visualization device. In some embodiments, theaugmentation device comprises at least one mesh, cage, barrier, patch,scaffold, sealing means, hydrogel, silicone, growth factor, orcombination thereof. In some embodiments, the augmentation device may bean ablation device, a balloon, or a temperature-controlled energyelement, for example. The energy element may be a thermal energy devicethat delivers resistive heat, radiofrequency, coherent and incoherentlight, microwave, ultrasound or liquid thermal jet energies to thenucleus.

In another embodiment, a method of diagnosing disc degeneration in apatient includes introducing a retractor cannula device permittingdirect visualization capability into a portion of the spine, steeringthe retractor cannula device using visualization information provided bythe retractor cannula device, displacing the neural tissues or othertissues with the retractor cannula device to create a working area, andassessing the targeted site. The retractor cannula device may comprise amaterial or marker to enhance visualization of the structure using animaging modality outside of the body. The method may include receivingvisualization information from an imaging modality outside of the body,such as fluoroscopy, CT and/or magnetic resonance imaging. Thevisualization information may also be provided by an image generated bya sensor located on the visualization device. The retractor cannuladevice may also include a sensor for collecting diagnostic data.

In another embodiment, a kit for augmenting the intervertebral disc mayinclude at least one disc augmentation device, a retractor cannuladevice having a tapered shape retractor assembly at its distal tip, anendoscopic mechanism having direct visualization capabilities, andinstructions for locating the at least one disc augmentation deviceusing the retractor cannula device. The kit for decompressing thenucleus of an intervertebral disc may also include at least one nucleusdecompression device, a retractor cannula device at its distal tip thatpermits direct visualization using an endoscope or other visualizationsystem, and instructions for decompressing the nucleus of anintervertebral disc using the retractor cannula device.

In another embodiment, a method for treating intervertebral discdegeneration includes introducing a retractor cannula device permittingdirect visualization into a portion of the spine using a visualizationmechanism, displacing the spinal tissue with the retractor cannuladevice to create a working area, and using the retractor cannula deviceto deliver a stimulation electrode device for treating intervertebraldisc degeneration. In one or more of the embodiments, the retractorcannula device may be steered to a position about the spinal column bydirect visualization of the visualization mechanism. The method may alsoinclude, steering the retractor cannula device using visualizationinformation provided by the visualization mechanism, displacing thetissues in spinal area with a portion of the retractor cannula device tocreate a working area, and using the retractor cannula device to delivera stimulation electrode device for treating intervertebral discdegeneration. The visualization mechanism, such as an endoscope, may beplaced into the retractor cannula device or may be integrally formedwith the retractor cannula device.

In another embodiment, a retractor cannula device for assessing a targetsite within the body may include a multi-lumen elongate shaft and aretractor assembly attached at a distal end of the shaft, wherein theretractor assembly is comprised of at least two jaws coupled to theshaft via any suitable articulation, including hinge structures, suchthat the jaws may have a closed configuration and an open configuration.In the closed configuration, the jaws may mate with one another suchthat a substantially smooth and rounded tip is formed. In the openconfiguration, the jaws are moved outward, increasing the angle betweentheir inner edges, which may be used to dilate tissue and to increasethe field of view.

In another embodiment, a retractor cannula device for visualizing atarget site within body may include a proximal portion and a distalportion, at least three lumens positioned within the proximal portion,wherein at least one lumen is configured for insertion of an endoscope,and at least one lumen is suitable for allowing passage of therapeuticinstruments or injection of medications. A retractor assembly may beattached to the distal portion of the retractor cannula device, and atleast part of the distal portion of the retractor cannula device may beconfigured such that in at least one configuration, the jaws of theretractor assembly may allow direct visualization. In some embodiments,the jaws of the retractor assembly are constructed of opaque ortransparent materials, for example any polyester copolymer (PETG, PETE),nylon, urethane, polycarbonate, acrylic, silicone, and/or glass.

In another embodiment, a retractor cannula device may include anelongate shaft having a proximal portion and a distal portion, whereinthe proximal portion contains four separate lumens, one of said lumensbeing configured for the passage of the endoscope and/or irrigationtherethrough, one of said lumens being configured for the passage oftherapeutic instruments and/or aspiration, one of the said lumens beingconfigured for the actuating members that manipulate the jaws of theretractor assembly, and one of said lumens for additional aspiration orirrigation. The distal portion of the retractor cannula device maycomprise lumen openings, with one of said lumen openings in continuitywith the lumen for the endoscope and/or irrigation, one of said lumenopenings in continuity with the lumen for therapeutic instruments and/oraspiration, and one of said lumen openings in continuity with the lumenfor additional aspiration or irrigation. The use of any one lumen neednot be limited to a particular instrument or procedure, and may be useddifferently from the exemplary embodiments disclosed herein. In someembodiments, two or more lumens may be used for the same purpose duringa procedure.

In one embodiment, a minimally invasive spinal endoscopy system isprovided, comprising a tubular shaft with a slotted flexion zone, atleast two slidable control wires, a proximal end, a distal end, at leasttwo irrigation channels, at least one non-circular instrument channel,and a visualization channel. In some examples, the tubular shaft mayhave an average diameter of less than about 3.5 mm, or less then 2.5 mm,or even less than 1.5 mm. The system may further comprise an actuatorattached to at least two slidable control wires, a housing enclosing theproximal end of the tubular shaft and at least a portion of theactuator, and a retractor assembly. The minimally invasive spinalendoscopy system may also further comprise a guidewire, a dilator, anintroducer sheath, a tissue debrider, a retractor assembly, acoagulation probe, and an infusion cannula configured for insertion intoat least one instrument channel.

In another embodiment, a minimally invasive device for use in a body isprovided, comprising a tubular body comprising a proximal end, a distalend, a first lumen therebetween, and a retractor assembly control lumen,and a retractor assembly with at least two jaws in communication withthe retractor assembly control lumen, a proximal end, and a distal end.The retractor assembly may also have a closed configuration with areduced profile and an open configuration with an enlarged profile. Insome examples, the retractor assembly may be biased to the closedconfiguration, the open configuration, or a third configuration. Theretractor assembly may comprise a rounded or tapered shape.

In one embodiment, a kit for performing a medical procedure may beprovided, comprising a cannula with a cannula lumen configured toaccommodate an endoscope, a distal retractor assembly with a workingspace, and a rotatable tissue removal device configured for insertionthrough the cannula and into the working space of the distal retractorassembly. The kit may also further comprise an endoscope configured forinsertion into the cannula.

In another embodiment, a method for minimally invasively accessing abody site is provided, comprising providing a tubular body with aretractor assembly located at a distal end of the tubular body andprotruding from the distal end of the tubular body, where retractorassembly has a closed and an open configuration, and the tubular bodycomprises a viewing lumen to retain an endoscope and a working spacedistal to the viewing lumen, inserting a tubular body toward anon-vascular target site in a body, urging the retractor assembly of thetubular body into an open configuration while in the body, andvisualizing the non-vascular target site from the tubular body andthrough the lumen of the retractor assembly. The method may alsooptionally comprise inserting an endoscopic device into the tubularbody. The method may also include advancing the distal end of thetubular body toward a neural structure in contact with a non-neuralstructure, and displacing the neural structure from the non-neuralstructure using the retractor assembly. The method may also compriseorienting the working space of the retractor assembly with thenon-vascular target site. In some embodiments, the method mayadditionally or alternatively comprise urging the retractor assemblyfrom a closed to an open configuration while in the body, andvisualizing the non-vascular target site from the tubular body andthrough a working space of the retractor assembly.

Another embodiment comprises a method for treating intervertebral discdegeneration in a spine, which may involve introducing a retractorcannula device having direct visualization capability into a portion ofa spine, wherein the retractor cannula device contains at least onelumen configured to encase an endoscope, urging the retractor assemblycannula into an open configuration to create a forward lookingcapability to enhance visualization and displacement of tissues, andintroducing a therapy device into the retractor cannula device to treatdisc degeneration. The therapy device may be any of a variety of therapydevices, including implants configured to provide structural support toa disc annulus of the spine, device configured to seal a torn annulus,and/or those instruments that add and/or remove additional material tothe nucleus.

In some embodiments, a method for treating intervertebral discdegeneration in a spine of a body may comprise making an incision into askin of the body, introducing a retractor cannula device with a directvisualization component into a portion of the spine, urging ormanipulating the retractor assembly into an open configuration to createa forward looking capability to enhance visualization and displacementof tissues, introducing a therapy device into the retractor cannuladevice, and treating the disc degeneration. In some embodiments, themethod may additionally or alternatively comprise manipulating theretractor assembly from a closed to an open configuration to provide anenlarged working space to augment tissue visualization and displacement.

In another embodiment, a method for treating intervertebral discdegeneration may comprise introducing a retractor cannula device havingdirect visualization capability into a portion of the spine, steeringthe retractor cannula device to a position adjacent an outer surface ofthe disc or nervous tissues using visualization information provided bythe retractor cannula device, displacing the nervous tissues or othertissues with a portion of the retractor cannula device to create aworking area, using the retractor cannula device to deliver a therapydevice for treating intervertebral disc degeneration, and treating thedisc degeneration. The therapy device may be a nucleus decompressiondevice to remove a portion of the nucleus, annulus, or fragmentedsegments, or a therapy device shrinks a portion of the nucleus orannulus, for example. More than one therapy device may be provided orused with the retractor cannula device. Treatment of the discdegeneration may comprise repairing a herniated disc, supporting adamaged annulus, sealing an annulus, adding material or removingmaterial with respect to the nucleus or annulus, and/or dilating ordisplacing spinal tissue using the retractor cannula device.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments herein are best understood from the following detaileddescription when read in conjunction with the accompanying drawings. Itis emphasized that, according to common practice, the various featuresof the drawings may or may not be to-scale. On the contrary, thedimensions of the various features may be arbitrarily expanded orreduced for clarity. In some figures, the same reference numerals may beused to denote related structures in different embodiments or examples.Included in the drawings are the following figures:

FIG. 1 is a perspective view of one variation of a retractor cannuladevice.

FIG. 2 is a perspective view of a distal portion of the retractorcannula device from FIG. 1.

FIG. 3A is a superior view of a distal portion of a retractor cannuladevice with a rounded retractor assembly. FIGS. 3B and 3C are side viewsof the distal portion of a retractor cannula device with a roundedretractor assembly in a closed configuration and an open configuration,respectively. FIG. 3D is a cross-sectional view of the device in FIG.3B, and FIG. 3E is a perspective ghosted view of the retractor assemblyin FIG. 3A. FIG. 3F is a component view of a rounded retractor element.

FIGS. 4A to 4F depict an embodiment of a retractor cannula device with atapered retractor assembly. FIGS. 4A and 4B are superior views of thetapered retractor assembly; FIG. 4C is a side view of the retractorassembly from FIGS. 4A and 4B. FIG. 4D is a side view of the taperedretractor assembly in both the closed (dotted lines) and open (solidlines) configuration. FIG. 4E is a perspective view of the retractorassembly in FIG. 4A. FIG. 4F is a component view of a tapered retractorelement.

FIG. 5A is a side view of an embodiment of a retractor elementcomprising tissue-engaging members. FIG. 5B is an inferior view of theretractor element in FIG. 5A.

FIG. 6 depicts one embodiment of a flexible region of a retractorcannula device.

FIG. 7A depicts another embodiment of a flexible region of a retractorcannula device; FIG. 7B is a detailed schematic view of the flexibleregion of FIG. 7A during flexion.

FIG. 8 depicts another embodiment of a flexible region of a retractorcannula device.

FIG. 9 is a schematic cut-away view of the housing of one embodiment ofa retractor cannula device.

FIGS. 10A to 10C are detailed views of various embodiments of a cannuladevice with a steering mechanism.

FIGS. 11A and 11B are schematic cross-sectional views of a retractorcannula device with an inserted endoscope in a neutral and a flexedposition, respectively.

FIGS. 12A and 12B depict one embodiment of the lumens and channelswithin the tubular body of a retractor cannula device.

FIGS. 13A-13C are cross-sectional views of various embodiments of amulti-channel tubular body.

FIG. 14 is a schematic representation of one embodiment of a retractorcannula device with two channels centered along a plane perpendicular toa bending plane of the retractor cannula device.

FIG. 15 is a schematic representation of one embodiment of a tubularbody of a retractor cannula device in a neutral position and in variousflexed positions within a bending plane (depicted with dashed lines).

FIG. 16 is a cut-away view of a retractor cannula device with tubesconnected to the tubular body.

FIG. 17 is a side elevational view of a retractor cannula device.

FIG. 18A is a cut-away view and FIG. 18B is a side elevational view ofone embodiment of a retractor cannula device with an endoscopic couplingport.

FIG. 19 is a schematic side cut-away view of one approach to thevertebrae.

FIG. 20 is a schematic superior cut-away view of one approach to thevertebrae.

FIGS. 21A and 21B depict a perspective and side view (respectively) ofanother variation of a retractor cannula device.

FIG. 22A is a side view of a distal portion of a retractor cannuladevice with an angled retractor assembly. FIG. 22B is a firstperspective view of the angled retractor assembly from FIG. 22A, andFIG. 22C is a second perspective view of the same angled retractorassembly.

FIG. 23A is a side view of one variation of a handle of the retractorcannula device from FIGS. 21A and 21B. FIG. 23B is a perspective view ofthe handle from FIG. 23A.

DETAILED DESCRIPTION

Conventional systems often rely on external visualization such asfluoroscopy and CT scanning for the approach to the disc, and thus lackany sort of real time, on-board visualization capabilities. Also,existing devices provide little in the form of tactile sensation for thesurgeon and do not allow the surgeon to atraumatically manipulatesurrounding tissue.

There is a need, therefore, for minimally invasive techniques andsystems that provide the capability to diagnose or repair the spineusing direct visualization while minimizing damage to surroundinganatomical structures and tissues. There is also a need for a method anddevice that allows a physician to effectively enter the epidural spaceof a patient, clear an area within the space to enhance visualizationand use the visualization capability to diagnose and treat the discinjury.

The embodiments disclosed herein will be more clearly understood andappreciated with respect to the following Detailed Description, whenconsidered in conjunction with the accompanying Drawings.

I. Retractor Cannula Device

A retractor cannula device may be used to deliver devices and therapies,such as devices for visualization/imaging, aspiration, irrigation,medication infusion, spinal disc augmentation, nucleus decompression,ablation, implantation, and the like. FIGS. 1 and 2 depict oneembodiment of a retractor cannula device 100, which may comprise atubular body 102 with a proximal end 104 and a distal end 106, aretractor assembly 116, and a handle 118. The proximal end of thetubular body 102 may be associated with one or more ports 108, 110, 112,and 114 via the handle 118. The distal end 106 may be coupled to theretractor assembly 116, one example of which is shown in FIG. 2.Retractor assembly 116 may be coupled to the tubular body 102 via aflexible region 124 that is configured to permit flexion of the distalend 106. The retractor assembly 116, examples of which are described ingreater detail below, may be used to create working space for theinsertion and movement of devices and direct visualization of a targetbody region. Space may be created by dissecting, deforming,manipulating, securing or atraumatically displacing surrounding tissue,structure, or anatomical features, for example. The retractor assembly116 may have two or more configurations, for example, an openconfiguration and a closed configuration. In some embodiments, aretractor assembly may be configured to be advanced over a guideelement, e.g., a guide wire, which may facilitate navigation of theretractor cannula device to the targeted body region. The ports 108,110, 112, and 114 may be in communication with one or more channels ofthe retractor assembly 116 via one or more lumens or channels in thetubular body, and may be configured for any of a variety of usages,including but not limited to infusion/drainage/suction of fluids ormaterials, insertion/removal or supporting an endoscope, fiber-optic orvisualization device, opening/closing of the retractor assembly, and forinsertion or removal or support of other instruments or tools.Atraumatic displacement of the tissue surrounding the targeted bodyregion by the retractor assembly 116 may increase the angle of view ofthe surrounding structures from an endoscope or other visualizationassembly located in the device 100, and may also help to improve theimages taken by an endoscope, e.g., by displacing structures a certainfocal distance from the endoscope.

The handle 118 may be any suitable handle structure, and may be providedat the proximal end 104 of the tubular body 102. In addition tosupporting the ports 108, 110, 112, and 114, the handle 118 mayfacilitate manipulation and use of the retractor cannula device throughone or more actuators, for example, buttons, slide actuators, dials,levers, and the like. In the particular embodiment depicted in FIG. 1,the handle comprises a lever 122 comprising two ends 188, which mayproject from the handle 118, but in other embodiments, any of a varietyof actuators may be provided. Levers, slide actuators, buttons and thelike may have any suitable geometry, and may be shaped or sized to beergonomic. For example, a slider 119 may be located to be easilyaccessible as shown in FIG. 1. These actuators may be used to controlthe use of the retractor cannula device, for example, to control asteering mechanism 120 or steering assembly. Handle actuators may alsobe used to navigate the tubular body (e.g., by bending or flexing), aswell as to control the configuration of the retractor assembly 116.During use, the retractor cannula device 100 may be advanced through theworking channel of a trocar or introducer and into the working area. Insome embodiments, the working area or space may be created by separatingstructures or tissue using an atraumatic retractor assembly, eitheralone or in combination with the steering mechanism 120. The steeringmechanism 120 may be configured to provide any of a variety of steeringfeatures, including various bending planes, various bending ranges,extension and retraction ranges, and rotations ranges, for example. Asmentioned previously, in the embodiment depicted in FIG. 1, the actuatorcomprises a lever 122 with both ends 188 projecting from the housing118, but in other embodiments, any of a variety of actuators andactuator configurations may be used, including but not limited to dials,knobs, sliders, buttons and the like, as well as electronic touchcontrols, for example. In some embodiments, only one end 188 of thelever 122 may project from the housing 118. The controls used tomanipulate the steering mechanism 120 may be manually manipulated by theuser or by a mechanical control system comprising various motors. Instill other embodiments, actuators such as the lever 122 may be omittedand the retractor cannula device 100 may be directly coupled to a motorcontrol system. These and other components of the retractor cannuladevice 100 are described in greater detail below.

The tubular body 102 may have one or more longitudinal channels spanningat least a portion therethrough. The longitudinal channels may be forhousing actuating mechanisms, providing communication between ports atthe handle to channels in the retractor assembly, or may be workingchannels. Working channels may be configured for the delivery of variousdevices, or example, dissection or biopsy instruments, and/orvisualization devices such as an endoscope. One or more working channelsmay be configured for the delivery of therapeutic agents or fluids forirrigation. The tubular body 102 may have a working channel that isconfigured for visualization functions, e.g., a visualization channel.Additional types of longitudinal channels and their arrangement will bedescribed in further details below.

As previously described, the retractor cannula device 100 may compriseat least one flexible region 124 which may help the retractor cannuladevice to maneuver efficiency through tissue and may help the retractorcannula device to be navigated atraumatically. In certain embodiments,the at least one flexible region may be situated distally on the tubularbody 102, e.g., proximal to the retractor assembly 116. This may permitthe tip, i.e., the distal portion, of the retractor assembly cannula toflex or bend, and may allow for 360 degree rotation around itslongitudinal axis. Such a configuration may permit the retractor cannuladevice to navigate to tortuous regions of the body, and may also allowthe device to torsion tissue gripped by the retractor assembly tore-position or remove it.

The retractor assembly 116 may also be used with the retractor cannuladevice 100 to provide therapy or treatment, and may shield surroundingtissue or provide access for the delivery of additional devices. Theretractor assembly 116 may be atraumatic, and may be positioned at thesurgical or treatment site in a compact or stowed condition (see, e.g.,FIG. 3B) and then deployed as necessary (see e.g., FIG. 3C).

Any suitable atraumatic structure may be used with the distal end 106 ofthe retractor cannula device 100 to help reduce the risk of inadvertentinjury to surrounding structures during a procedure. For example, anatraumatic retractor assembly may be configured to provide tactilefeedback, e.g., rigidity, pliability or feel of the tissue or structuresin contact with the distal-most portion of the retractor assembly, tothe user. In one embodiment, an atraumatic retractor assembly may alsoprovide dissection or retraction capabilities and may be able todisplace surrounding tissue without injuring it. Additionally, theoverall shape of an atraumatic retractor assembly may allow manipulationof nerves, e.g., nerves in the proximity of an intervertebral disc, asthe retractor cannula device is advanced without harming the nerve orcausing pain. In one embodiment, a retractor assembly may have a curvedshape and no sharp edges, burrs or other features that may pierce, snag,tear or otherwise harm tissue that comes into contact with the retractorassembly. The shape, surface contours and/or overall finish of anatraumatic retractor assembly may be selected to help reduce or minimizeimpact forces when the tip, i.e., the distal portion of the retractorcannula device, comes into contact with structures such as nerves,muscle and the spinal dura, among others.

The atraumatic element at the distal end 106, e.g., the retractorassembly 116, may also be controllably pivoted or actuated from theclosed configuration to the open configuration, or otherwise comprisetwo or more surfaces or structures that are independently controllable.For example, the retractor assembly 116, which may be urged from aclosed configuration to an open configuration to create a working spacein the surrounding tissue, which may act as a clearing for improvedvisibility of any suitable visualization devices provided therein. Oncea target tissue is positively or at least sufficiently identified, theretractor cannula device may then be advanced to the target tissue ineither the closed or open configuration, as appropriate, to create afirst working space. The retractor assembly may then be actuated to theopen configuration to create a second working space and so forth toadvance the retractor cannula device towards a targeted body region,e.g., to advance the retractor cannula device in a spinal space. Inaddition, the retractor cannula device may be used to provide saline oranother type of cleaning solution or a contrast agent to the workingarea for enhancing visualization. In certain embodiments, the retractorassembly 116 may be moveable or articulated such that it may be used todisplace surrounding tissue or structures. The displacement of tissue orstructures may be felt by the user and may provide a more tactile senseof tissue movement or displacement. The tissue displacement may resultfrom active movement of the retractor assembly under control of theuser, or movement caused by releasing the retractor assembly from afirst biased position to a second position. Other conventionaltechniques for manipulation of surgical implements may also be used tocontrol the retractor cannula device.

Another variation of a retractor cannula device is shown in FIGS. 21Aand 21B. Retractor cannula device 2100 may comprise a tubular body 2102with a proximal end 2104 and a distal end 2106, a retractor assembly2116, and a handle 2118. As with the retractor cannula device 100, theproximal end 2104 of the tubular body 2116 may be associated with one ormore ports at the handle 2118, for example, handle port 2123 andauxiliary port 2128. The ports and the handle 2118 may be configured toaccommodate various devices, for example, a device coupler 2122 may beprovided to help attach a device (e.g., an endoscope) to the handle2118. The handle 2118 may comprise actuators for the navigation andactuation of the distal end 2106 of the tubular body 2102 (e.g., theretractor assembly 2116), such as a pivot lever 2124 which may beconfigured to control the configuration of the retractor assembly 2116.As shown in FIG. 21B, a spring 2132 may be provided to bias the pivotlever 2124 into a certain configuration. A pivot lever lock 2125 mayalso be included as desired for restricting the actuation of the pivotlever 2124. Other actuators, such as levers, sliders, buttons, and thelike may also be included as appropriate.

The various components of the retractor cannula devices described abovemay be made from any suitable materials. For example, the tubular bodyand/or the retractor assembly may be made of a rigid material, such asstainless steel or rigid plastic. The flexible region 124 may be made ofany combination of flexible biocompatible polymers or pliable metals. Insome embodiments, the flexible region may be actuated by wires or strutswithin the tubular body, or by sliding other elongate members providedin the tubular body, for example. Alternatively or additionally, thetubular body may be strong and flexible, and may be made of acombination of materials, such as stainless steel metal braid embeddedin elastic polymers. Examples of elastic polymers may be (but are notlimited to) Pebax, polyurethane, and silicone.

The dimensions of the various components of a retractor cannula device,such as the retractor assembly, flexible region, tubular body, handle,etc., may be sized and selected based on the particular therapy beingprovided and the targeted body region. For example, one embodiment ofthe retractor cannula device may have dimensions suitable for navigationto a spinal region for diagnostic evaluation and/or to apply a therapythereto. In another embodiment, the retractor cannula device may besized to fit within an epidural space or in proximity to anintervertebral disc. Other embodiments may be configured for use in thechest cavity (e.g. pleural biopsy or pleuracentesis) or abdominal-pelviccavity (e.g. bladder neck suspension), or for non-spinal procedures suchas breast biopsy and transvaginal oocyte retrieval, for example. In someembodiments, the retractor cannula device 100 may have a diameter ofabout 5 mm or less, while in other embodiments, the retractor cannuladevice may have a diameter of about 3 mm or less, or even 2.5 mm orless. In another embodiment, one or more of the working channels of theretractor cannula device 100 may have a diameter of about 5 mm or less,about 3 mm or less, about 2 mm or less, about 1 mm or less, or about 0.8mm or less. Additional details and descriptions of the variouscomponents of a retractor cannula device are provided below.

A. Retractor Assembly

The retractor cannula device 100 may be used to manipulate a targetedbody region in different ways. For example, the retractor cannula devicemay be used to dilate and/or displace tissue to create a working space,aspirate and/or irrigate the target tissue, infuse medications, injectsubstances, remove tissue, etc. Furthermore, the retractor cannuladevice may be used to deliver a variety of devices to a target tissue,for example, any visualization devices (e.g., endoscope), ablationdevices, expandable devices, thermal energy devices, stimulationelectrodes, etc. Different retractor assemblies may be used with theretractor cannula device to effect one or more of the above functions.For example, a retractor assembly may have one or more retractorelements, e.g., jaws, and may have one or more configurations forperforming different functions, e.g., an open configuration and a closedconfiguration. By transitioning the retractor assembly from a closed toan open configuration, the retractor elements of a retractor assemblymay be urged outwardly against the surrounding tissue to provide a spacefor direct visualization and/or the insertion of additional devices. Insome variations, an atraumatic retractor assembly may cycle between theclosed and open configuration to assist in the advancement of theretractor cannula device. In some cases, the operation of the retractorassembly may take place with the assistance of direct visualization,such as images from an endoscope. Some variations of an atraumaticretractor assembly may comprise working channels that are incommunication with one or more channels or lumens in a tubular body of aretractor cannula device. Longitudinal lumens or access lumens, e.g.,the channels 1326, 1328, and 1330 in FIG. 13A may extend through thelength of the tubular body, and may be in communication with theretractor assembly. These channels may be sized to allow passage of thecatheters, endoscopes, and instruments/devices, and the like.

The shape and size of a retractor assembly may vary according to thetissue environment (e.g., thin vs. thick tissue, regions of denselypacked tissue structures vs. sparsely-distributed tissue structures,volume of liquid media in the vicinity of the target tissue, elasticityof the target tissue, etc.). In some variations, the surface of theretractor assembly may be have one or more curves, where the curvatureof the retractor assembly surface (e.g., in the closed configuration)may be uniform around the longitudinal axis of the retractor cannuladevice, or may be non-uniform around the longitudinal axis. For example,the surface of the retractor assembly may be tapered along a firstsurface with first angle or slope, and may be tapered along a secondsurface with a second angle or slope, where the first and second anglesor slopes may not be equal. Tapers may have one or more angles orslopes, and curvatures may have one or more radii of curvature. In somevariations, the surface of a retractor assembly may have a widerdimension on a first side, and a narrower dimension on a second side.While certain examples of retractor assemblies are described below, withcertain shapes and curves, it should be understood that other types ofretractor assemblies may be used with a retractor cannula device, andmay vary according to the desired functionality as well as the targetedbody region or tissue, e.g., have different sizes, different shapes,different curves, and numbers of longitudinal channels, etc.

1. Rounded Retractor Assembly

One embodiment of a retractor assembly is shown in FIGS. 3A to 3F. Asuperior view of retractor assembly 300 is shown in FIG. 3A, a side viewof retractor assembly 300 is shown in FIG. 3B, and a perspective view inFIG. 3E. As depicted there, the retractor assembly 300 comprises tworetractor elements, jaws 308 and 310, shaped such that when in theclosed configuration, jaws 308 and 310 mate to form a substantiallysmooth round shape, similar to a bullet, where the curvature of the jawsurfaces is uniform around the midline 399 of the tubular body 102. Thesurfaces of the jaws 308 and 310 may be symmetrically curved such thatthey meet at a distal portion 302. Additionally or alternatively,embodiments of a retractor assembly may comprise one or more retractorelements, such as paddles, flaps, lobes, tabs, jaws, and the like. Theretractor assembly 300 may have jaws shaped with one or more curvedsurfaces as described above, such as a sphere, dome, tapered ellipticalshape, or any other shape that may help to reduce trauma to surroundingtissue. The rounded retractor assembly is shown in FIGS. 3A and 3B, andeach of the jaws 308 and 310 are shaped as a half sphere, as depicted inFIG. 3F. FIG. 3F is an enlarged depiction of jaw 308 with inner edge 309(jaw 310 and inner edge 311 are minor reflections of jaw 308 asdepicted). Other atraumatic geometries, which are described below, mayalso be used.

The jaws 308 and 310 may have one or more configurations, for example, aclosed configuration (as depicted from the side in FIG. 3B, and inperspective in FIG. 3E), and an open configuration, (as depicted in FIG.3C). Although the jaws 308 and 310 in FIG. 3B are contacting each otheraround their outer edges when in the closed configuration, in otherexamples, the jaws may not fully close. While the jaws 308 and 310 areshown to open and close symmetrically about the midline 399, in othervariations of a retractor assembly, the jaws may not move between theopen and closed configuration symmetrically. In the open configuration,a working space 136 may be provided between the two jaws 308 and 310. Itshould be understood that the retractor assembly 300 may comprise morethan two jaws, including three or more jaws that may be shaped such thatthe distal portions 302 of the jaws form a smooth, round, and atraumaticshape in the closed configuration. The jaws 308 and 310 may be coupledto the tubular body 102 using a hinge mechanism 306. Each jaw may becoupled to the tubular body 102 by one or more hinges (306 a and 306 b)configured in any suitable way to expose or present the working space136 when transitioned between the closed configuration and the openconfiguration. In some variations, jaws and any other retractor elementsmay be coupled to tubular body 102 by pins, mandrels, screws, etc.

In certain embodiments, a hinge mechanism 306 may comprise living hingesand/or mechanical hinges formed by rivets, pins, or screws, for example.The hinge mechanism may be made of any suitable material. In one exampleshown in FIGS. 3B and 3C, the hinge mechanism 306 comprises hinges 306 aand 306 b which may lie flush against the outer surface of the tubularbody 102. The hinges 306 a and 306 b may be configured such that whenthe jaws 308 and 310 are transitioned into the open configuration, asshown in FIG. 3C, one or more distal portions 302 of the jaws 308 and310 may move away from the other, or move away from the midline 399 ofthe device, i.e., move away from each other symmetrically, exposing theworking space 136. As previously described, the jaws 308 and 310 maymove away each other in asymmetrically, i.e., move away from each otherfrom a longitudinal axis that is parallel to the midline 399. In oneembodiment, as illustrated in FIG. 3C, the inner edges 309 and 311 ofthe jaws 308 and 310 form an angle, and in the open configuration, thisangle may be about 90 degrees. In other embodiments, the angle formed bythe inner edge 309 and the inner edge 311 may be any value from about 1to about 359 degrees, including about 60 degrees, about 90 degrees,about 120 degrees, about 180 degrees, or 270 degrees. The hingemechanism 306 of the retractor cannula device may be made of metal orplastic, or other similar suitable materials. In addition to mechanicalhinges that comprise a rivet upon which the hinges 306 a and 306 brotate, some embodiments may utilize a living hinge. The living hingemay comprise any material that can be fashioned into a thin, flexiblestrip, which may comprise the same or different material as theinstrument shaft, and may be a metal, plastic or other polymer. In someembodiments, other articulations may be used, including ball-and-socketjoints. In certain embodiments, the articulation between the tubularbody 102 and the jaws 308 and 310 may be configured to be slidable alongthe tubular body 102 for additional maneuverability. Additionally oralternatively, the entire retractor assembly may be configured to beslidable along the tubular body, with or without jaw angulation. Forexample, the retractor elements of a retractor assembly may be coupledto a tubular body via a flexible region.

In some variations, when the retractor assembly 300 is in an openconfiguration, the jaws 308 and 310 are configured to provide a workingspace that may help to improve the field of view of any visualizationinstrument that may be used with the retractor cannula device. Forexample, where a visualization device (e.g., an endoscope) is providedbetween the jaws 308 and 310 in the proximity of the working space 136,the retractor assembly 300 in an open configuration may provide aforward-looking capability, which may help enhance the visualization anddisplacing it. This forward-looking capability may be adjusted accordingto the tissue to be visualized and displaced by varying the anglebetween the inner edges 309 and 311, adjusting the flexibility of thehinge mechanism 306, and/or varying the size and shape of the jaws 308and 310, and other related factors.

In some embodiments, the working space 136 is in communication with thetubular body 102. Referring to FIG. 3D, which depicts a cross-section ofthe retractor assembly 300 along line 3D-3D shown in FIG. 3B, certainembodiments of a retractor cannula device may have an inner shaft 316within a lumen 312 of the tubular body 102 that may help to support anystructures that control and/or navigate the retractor assembly andactuate the jaws 308 and 310. The inner shaft 316 may be axiallyslidable along the longitudinal axis (A_(L)) to actuate the motion ofthe jaws 308 and 310, and may be in communication with working space136. For example, the lumen 312 or the inner shaft 316 may house atleast a portion a jaw actuating mechanism. One example of a jawactuating mechanism is depicted in FIG. 3D. As shown there, the innershaft 316 comprises a tab 315 that may articulate with pins 314, wherethe pins 314 may be coupled to the jaws 308 and 310. Sliding of theinner shaft 316 may translate the tab 314, which may rotate the pins 314so that the jaws 308 and 310 may pivot outwardly (i.e., may move awayfrom the other, or move away from the longitudinal axis (A_(L)) of thedevice). The inner shaft 316 may be controlled using an actuator on thehandle 118, for example, the slider 119. Other embodiments may use otheractuating mechanisms, for example pull wires or struts, to open or closethe jaws. The pull wires may include metallic or polymeric wires, whichmay be single-stranded or multi-stranded, and may included twisted orbraided members. In still other examples, the movement of the jaws maybe asymmetrical (e.g., one jaw may be biased into one position while theother jaw is unbiased, etc.) or one or more jaws may be immovable whileone or more other jaws are movable.

2. Tapered Shape Retractor Assembly

Another embodiment of a retractor assembly 401 is depicted in FIGS. 4Ato 4F. The retractor assembly 401 comprises two retractor elements, jaws408 and 410. Additionally or alternatively, embodiments of a retractorassembly may comprise one or more retractor elements, such as paddles,flaps, lobes, tabs, jaws, and the like. The jaws 408 and 410 havecurvatures that are non-uniform around the midline 499. As shown inFIGS. 4A and 4B, the jaw 408 is tapered with one or more slopes orangles along a longitudinal axis, e.g., midline 499. As shown in thesuperior view in FIG. 4A, the retractor assembly 401 has a firstcurvature on a first profile of the jaw 408, where the first curvaturehas a first taper that is generally smooth and rounded towards a distalportion 402, and a second taper that is rounded at a distal portion 402.FIG. 4B is a close-up view that shows where the jaw 408 may be taperedtowards a distal portion 402, e.g. the taper of the jaw 408 may be flatproximally and steep distally. FIG. 4C depicts a side view of theretractor assembly 401 that is perpendicular to the views shown in FIGS.4A and 4B. As shown there, the surface curvature of the jaws 408 and 410are different from the surface curvature as seen from a superior view ofthe retractor assembly 401, i.e., the curvature of the jaw surfaces arenon-uniform around the midline 499. From the side view, the retractorassembly 401 has a more gradual or uniform taper along a second profileas compared to the first profile shown in FIGS. 4A and 4B. This may beseen also in FIGS. 4E and 4F. While the jaws 408 and 410 have at leasttwo different curved surfaces (e.g., a first tapered surface shown froma superior view, and a second tapered surface shown from a side viewperpendicular to the superior view), in other embodiments, thecross-sectional or side profile may be more or less tapered that thetaper from the superior profile, where the taper of the jaws 408 and 410may increase proximally and/or decrease distally. In other embodiments,any tapered or non-tapered configuration may be used. While jaws 408 and410 may have symmetric tapers on two orthogonal jaw surfaces, other jawvariations may have symmetric tapers on more than two jaw surfaces(which may or may not be orthogonal), and/or may have asymmetric tapersas suitable for atraumatically navigating through the target tissueenvironment. In this particular example, the jaws 408 and 410 have across-sectional profile with an acute angle (see FIG. 4F), where theapices form a flat tapered tip 404 in the closed configuration, as shownin FIG. 4C.

As described with respect to retractor assembly 300, retractor assembly401 may have the same or similar configurations. The open configurationis illustrated in the solid lines of FIG. 4D, showing the action of thejaws 408 and 410, while the dotted lines represent the location of thejaws 408 and 410 in the closed configuration. The jaws may be urged intothe open configuration by a rotating hinge 406 in the direction ofarrows 405 and 403, where an angle is created between the edges 409 and411, and the jaws assume the open configuration. In the openconfiguration, the angle between edges 409 and 411 may be any value fromabout 0 degrees to about 270 degrees or more, including up to about 30degrees, about 60 degrees, about 90 degrees, about 120 degrees, about180 degrees, about 270 degrees, or more. As mentioned previously, insome embodiments, both jaws 408 and 410 need not open or closesymmetrically, and in some embodiments, one or both jaws may even have afixed location relative to the tubular member 102. The actuatingmechanism of the retractor assembly 401 may be the same or differentfrom the actuating mechanisms disclosed for the retractor assembly aspreviously described and depicted in FIG. 3D. Hinge mechanisms,configurations, functions, and their actuation have been described andshown previously, e.g., in FIG. 3D.

3. Angled Retractor Assembly

In certain embodiments of a retractor assembly, the jaws may not besymmetric about a midline of the device in shape or movement. FIGS.22A-22C depict an angled retractor assembly 2200 in an openconfiguration, where the angled retractor assembly 2200 comprises afirst jaw 2208 that has an angle 2203, and a second jaw 2210 that doesnot have an angle. In some embodiments, the second jaw 2210 may beoptional. The first jaw 2208 may comprise a rounded tip 2204, where theshape of the rounded tip 2204 is such that a rounded tip cavity 2212 isprovided therein. The angle 2203 may have any angle between 1 degree and180 degrees, for example, from about 150 degrees to about 179 degrees,or from about 100 degrees to about 130 degrees, or about 120 degrees toabout 160 degrees, or from about 90 degrees to about 120 degrees. Asindicated previously, the angled retractor assembly 2200 is shown herein its open configuration. When actuated to its closed configuration, atleast a portion of the first jaw 2208, e.g., the rounded tip 2204, mayextend beyond the midline 2207. This may help the retractor assembly2200 to grasp and/or hook tissue in the rounded tip 2204. The degree towhich tissue is engaged may be adjusted by varying the angle 2203, alongwith other features, as will be described below. In some variations, theextension of the first jaw 2208 beyond the midline 2207 may not enclosethe retractor assembly 2200, where even in the closed configuration,fluids or devices in the one or more lumens of the tubular body 2202 maystill exit the retractor assembly 2200. For example, in the closedconfiguration, the first jaw 2208 and the second jaw 2210 may form aside aperture, and in variations with a single jaw, the jaw 2209 mayform a side aperture with the tubular body 2202. The shape of the firstjaw 2208 is such that a first jaw cavity 2209 is contained therein, andas depicted in FIG. 22B, the first jaw cavity 2209 and the rounded tipcavity 2212 may be in communication with each other. The rounded tip2204 may also have a rounded tip hole 2214, as seen in FIG. 22C, thatmay be used to infuse a flush solution or contrast agent. The workingspace 2230 may be generally defined as the region between the first jaw2208 and the second jaw 2210, and may include the rounded tip cavity2212 and the first jaw cavity 2209, as well as any additional spacecreated by the retractor assembly 2200 as it dilates tissue.

As with the other retractor assembly embodiments, the first jaw 2208 maybe attached to the tubular body 2202 by a hinge 2206 on the side, aswell was a secondary hinge 2205 on the top, as depicted in FIG. 22C. Insome variations, the hinge 2206 may be a mechanical hinge, e.g., a pin,screw, a rotatable member, and the like, and the secondary hinge 2205may be a living hinge that may bend, but not rotate. In general, anysuitable hinge mechanisms may be used that allow the retractor assembly2200 to open, close, and bend as desired. While second jaw 2210 as shownin FIGS. 22A-22C is shown to be fixedly coupled to the tubular body2202, in other embodiments it may also be coupled to the tubular body2202 by a hinge mechanism. Second jaw 2210 may be significantly shorterin length than first jaw 2208, but in other variations, the size of eachof the jaws with respect to each other may be varied according to thedesired level of tissue grasping, dilating, and manipulating. In someembodiments, the first jaw 2208 and the second jaw 2210 may be made of aclear material, i.e., optically transparent, so that even in the closedconfiguration, a visualization device (e.g., an endoscope) containedtherein may still be able to acquire images. The first jaw 2208 and thesecond jaw 2210 may comprise additional features and have additional ordifferent configurations, as will be described later on.

In other embodiments of a retractor assembly, the retractor assembly maybe an extendable structure, where the extendable structure may beprovided with one or more support elements. The support elements may beoriented longitudinally, radially, and/or circumferentially along theretractor assembly jaws to support the various configurations the jawsmay take on. The configuration of a support element may be complementaryto the shape or configuration of the retractor assembly. In oneembodiment, the support element may comprise a helical configuration,for example. In some embodiments, the support elements may be locatedabout a tubular body lumen (e.g., lumen 312). The support elements maycomprise any of a variety of materials, including but not limited to ametal and/or polymeric material. The support element maybe rigid,semi-rigid or flexible, and at least a portion of the support elementmay be attached or coupled to the shaft, the inner or outer surface ofthe retractor assembly, and/or embedded in the inner edges of theretractor assembly.

4. Retractor Assembly Configurations and Mechanisms

As described above, retractor assemblies may have one or more retractorelements, for example, jaws, that may assume any size or geometry asappropriate for atraumatic manipulation of and navigation throughtissue. While examples of mechanisms for actuating a retractor assemblyhave been described above, other mechanisms may be used to position theretractor assembly in a variety of configurations for various functions.In certain embodiments, a mechanism that actuates a retractor assemblymay be biased towards one configuration or the other, or to a thirdconfiguration. For example, the jaws or retractor elements may be biasedtowards a closed configuration, such that in the absence of an actuatingforce, the retractor assembly remains in the closed configuration, andassumes the open configuration when it is actuated. A retractor assemblywith a bias towards the closed configuration may be used to manipulateand/or grab tissue, for example, for removal or replacement. In otherembodiments, the retractor members may be biased towards an openconfiguration, such that in the absence of an actuating force, theretractor assembly remains in the open configuration, and assumes theclosed configuration when actuated. A retractor assembly with a biastowards the open configuration may be used, for example, as a dilator ordisplace tissues or structures. A variety of bias mechanisms may beutilized as common in the art, for example, a spring may be used tomaintain the retractor member(s) in a particular configuration (e.g.,the bias spring 2132 shown in FIG. 21B), but forces may be applied toovercome the spring force and to transition the retractor member(s) toan alternate configuration. The spring or other bias member may actdirectly on one or more jaw members, or may act on the actuator locatedin the proximal housing of the device. Of course, certain embodimentsmay lack a bias to a configuration. In some embodiments, the retractorassembly may be releasably lockable into one or more configurations. Forexample, the jaws may be lockable in a variety of angled positionsbetween their inner edges, from about 0 to about 180 degrees or more,including but not limited to about 60, about 90, about 120, about 180,or about 270 degrees. The movement range of each retractor member may bethe same or different. In certain examples of retractor assemblies, oneor more retractor elements may have a fixed position, while one or moreother retractor elements may be movable. For example, in reference toFIG. 4D, both the jaws 408 and 410 are movable or pivotable to create anangle between the inner edges, however it should be understood that inother embodiments, either jaw may have a fixed position, while the otherjaw is movable. In reference to FIG. 22A, the jaw 2210 may be fixed in agiven location, and the jaw 2208 may be pivoted about the hinge 2206 toobtain a desired configuration.

The working space provided by the retractor assembly may becharacterized with respect to the geometry and configuration of theretractor elements, e.g., jaws. In certain embodiments, the workingspace may be characterized as the aggregate space directly between anytwo regions of different retractor elements. The working space may varydepending upon the particular configuration of the retractor elements.In some embodiments, the retractor assembly may characterized by themaximum working space achievable by the retractor assembly within itsmovement range, where the maximum working space may provide aforward-looking capability that may help to enhance visualization anddisplacement of tissues. The actual working space and/or maximum workingspace of an instrument may be restricted or limited by the surroundingtissues or structures. One of skill in the art will understand that theworking space or the maximum working space may or may not correlate withthe maximum viewing ability provided the retractor assembly. Forexample, the working space when the jaws are about 180 degrees apart maybe low, but the position of the jaws may substantially displace greateramounts of tissue away from the endoscope tip than the jaw angle whichprovides the maximum working space. Thus, in some instances, theeffective viewing space may be bordered by the displaced and undisplacedtissues surrounding the distal end of the cannula device. In someembodiments, it should be understood that the working space may varywith the geometry of the retractor assembly, for example, retractorassemblies with an elongate and/or tapered or rounded jaw configurationmay dilate tissue more than retractor assemblies with a shorter jawconfiguration. In some embodiments, the inner edges of the jaws maycomprise a smooth, rounded surface, which may help reduce the risk ofinadvertent snagging of tissue by the retractor assembly. In certainembodiments of retractor elements, the inner edge of the retractorelements may be configured with a variety of tissue-engaging members.Tissue-engaging members may be useful for dissecting and/or removing aportion of target tissue, for example, during the repair ofintervertebral discs or for tissue biopsy. In other embodiments, inneredges of the jaws may have tissue-engaging members, where thetissue-engaging members may not be smooth, for example, tissue-engagingmembers may be hooks, claws, graspers, teeth, and the like. One exampleof tissue-engaging members that may be used with a retractor assembly,e.g., retractor assemblies 300 or 401, is shown in FIGS. 5A and 5B. Asdepicted there, the inner edge 502 of retractor assembly jaw 500 may beprovided with tissue-engaging teeth 504. The location and orientation ofthe teeth 504 in the inner edge 502 may help to reduce the risk ofinadvertent tissue snagging while actuating jaw(s) 500 for thedisplacement and/or dilation of tissue. The jaw 500 may be used toengage tissue (e.g., for removal, dissection, biopsy, and the like)using teeth 504. The use of the teeth 504 may be controlled by one ormore buttons, slide actuators, dials, levers, etc. of the handle 118, asdescribed previously. While one example of tissue-engaging members areillustrated in FIGS. 5A and 5B, in other examples, tissue-engagingmember may have different geometries and arrangements as appropriate forengaging the target tissue. In certain embodiments, as shown in FIGS. 5Aand 5B, the teeth 504 may be angled with sharp/blunt vertices, as shownin FIG. 5A, but may be of any suitable geometry, e.g., domed,trapezoidal, helical, and the like. Also, the teeth 504 may be uniformlyset at a slant with respect to the inner edge 502 to optimally securetissue after initial contact, but it should be understood thattissue-engaging members may be set in alternate conformations, forexample, tissue-engaging members may be non-uniformly set with differentslants or no slants, and the tissue-engaging members may be ofnon-uniform shapes. The degree to which the teeth 504 extend beyond theinner edge 502 may vary, with some extending beyond the edge 502 asshown in FIG. 5A, but in other embodiments, tissue-engaging members maynot protrude or extend beyond the edge 502. The tissue-engaging memberson the inner edge of the retractor elements may be set a suitabledistance away from the edge to limit trauma to surrounding tissue duringthe navigation of the retractor cannula device towards the target bodyregion. In some embodiments, the tissue-engaging members on the inneredge are set approximately about 0.1 mm to about 1 mm or more away fromthe inner edge 502 of jaw 500. In some embodiments, tissue-engagingmembers, e.g., teeth 504, may be arranged along the perimeter of inneredge 502, as depicted in in FIG. 5B which shows a bottom view of jaw408. As shown there, teeth 504 may be arranged to tile a portion of theinner cavity of the jaw. It should be understood that any arrangement,and any density (which may or may not be homogeneous in the entire inneredge 502) of tissue-engaging members may be used in the inner edge. Theteeth 504 may be made of the same material as the jaw 500, but may alsobe made of different materials. Additionally or alternatively, othersurface enhancements and coatings may be applied to the inner edge ofthe retractor elements and/or protrusions, such as hydrophilic orhydrophobic materials.

In some embodiments, the retractor elements and any tissue-engagingmembers provided in their inner edge, may be made of any transparentpolymer, such as (but not limited to) polyester copolymers (PETG, PETE),nylon, urethane, polycarbonate, acrylic, and/or silicone. In someembodiments, the retractor elements may be made of an opaque material.Alternatively or additionally, the retractor elements may have a metalframe which may then be covered with one or more of the aforementionedpolymers. The frame may be made of (but not limited to) stainless steel,titanium alloy, cobalt chromium, tungsten, tantalum. In certainembodiments, at least a portion of the retractor elements may be made ofglass. Alternatively or additionally, the retractor elements may beconstructed of radio opaque materials to allow visualization of thedistal tip of tubular body 102 in X-ray imaging. In other embodiments,the retractor elements include a marker or other feature(s) making allor a portion of the retractor elements perceptible using externalimaging modalities. In another embodiment, the marker or feature is aradio opaque marker. Alternatively or additionally, the retractorelements may be constructed of materials that are readily resolved byultrasound or other imaging modalities. In some embodiments, someportion of the jaw (e.g. distal/forward-looking portion) may be made ofa soft material to minimize trauma to surrounding tissue.

The distal portion of retractor elements, e.g., jaws as shown in FIGS.3E and 4E, may be selected from a material that is transparent, whichmay be desirable for the operation of the port components, such as forvisualization devices. In some embodiments, the retractor assembly maybe formed from rigid, clear plastic, while in other embodiments, theretractor assembly may comprise a flexible, deformable material. In someembodiments, the retractor assembly comprises an opaque material, but inother embodiments may be translucent or transparent, which mayfacilitate the visualization of the tissue or structures adjacent theretractor assembly. The distal portion of the retractor assemblymaterial may be stainless steel, cobalt chromium, titanium,nickel-titanium, polycarbonate, acrylic, nylon, PEEK, PEK, PEKK, PEKEK,PEI, PES, FEP, PTFE, polyurethane, polyester, polyethylene, polyolefin,polypropylene, glass, diamond, quartz, or combination thereof, forexample. In some embodiments, the retractor assembly materials mayinclude the addition of one or more radiographic markers or materials.

Although the retractor assemblies 300 and 401 may be generallysymmetrical about the longitudinal axis of the tubular body 102, inother embodiments, the retractor assembly may be asymmetrical, such asretractor assembly 2200. Other retractor assembly jaw configurations mayalso be used, and slits or windows may be optionally provided toincrease direct visualization. For example, the retractor assemblyconfiguration may be altered using different jaw shapes, variable wallthickness and/or by pre-forming curves or fold along one or more regionsof the jaw material. In certain embodiments, the retractor assembly mayhave small apertures, such as slits, near the distal tip to allow forirrigation or administration of therapeutic agents to the target site.As such, the retractor assembly at the distal-most portion of theretractor cannula device may vary in structure and size. In somevariations, a retractor assembly may be sized and shaped to help reduceunintended trauma to the target tissue.

As described previously, the jaws of a retractor assembly may beactuated using levers, slide actuators, buttons, etc. provided at ahandle, e.g., handle 118. In some variations of a retractor cannuladevice, the retractor assembly may be steerable, and the retractorcannula device may be maneuvered using a steering mechanism, e.g.steering mechanism 120, to navigate through and/or manipulate tissue.For example, the retractor assembly may be in a closed configuration tofacilitate insertion of the retractor cannula device through folds oftissue, and may be opened to create a space between the folds of tissue.In some variations, a practitioner may advance the retractor cannuladevice under direct visualization to manipulate, dilate, and/or displacesurrounding tissue to create a working space in a tissue region. As theretractor assembly of the retractor cannula device expands its jaws froma closed to open configuration, a working space or opening may becreated in the surrounding tissue, thereby easing the advancement oratraumatic maneuverability of the retractor cannula device. Thereafter,the atraumatic retractor assembly may be deployed or otherwise used todeform surrounding tissue and/or to make space available (e.g., bydisplacing or dilating the surrounding tissue) for the retractor cannuladevice or other treatment device provided by one or more workingchannels in a tubular body. It is contemplated that one or more of thesemethods may be used in combination to manipulate the surrounding tissue.Any of a variety of other methods for utilizing the retractor cannuladevice are also contemplated, some examples of which are describedbelow.

Embodiments of a retractor cannula device may navigate through andmanipulate tissue under direct visualization, which may help tofacilitate the positioning of an instrument in a targeted area. In someretractor cannula devices, a visualization channel may be provided toaccommodate any suitable/appropriate imaging devices, e.g., endoscope.For example, the instrument may be steered using information, suchimaging or physiological information, provided by the instrument. Theimage may come from a fiber optic line or bundle, or a data device suchas a camera placed on the distal end of the instrument, or from a sensoror combination of sensors. In one embodiment, the sensor utilizes lightto generate the image. In another embodiment, the sensor is adapted tosee through the bloody field as presented in the spinal region byselecting at least one infrared wavelength transparent to blood or otherbodily fluids. In some embodiments, at least one infrared wavelengthtransparent to blood presented in the spinal field may have a wavelengthof about 1 micron to about 15 microns. In another embodiment, the atleast one infrared wavelength transparent to blood presented in thespinal field has a wavelength between about 1.5 micron to about 6microns. In yet another embodiment, the at least one infrared wavelengthtransparent to blood presented in the spinal field has a wavelengthbetween about 6 microns to about 15 microns. In yet another embodiment,the at least one infrared wavelength transparent to blood presented inthe spinal field has a wavelength between about 1.0 microns to about 1.5microns, about 1.5 microns to about 1.9 microns, about 2.0 microns toabout 2.4 microns, about 3.7 microns to about 4.3 microns, or about 4.6microns to about 5.4 microns. In yet another embodiment, the wavelengthis selected or adapted for use in distinguishing nervous tissue fromsurrounding tissue and/or minimally vascularized nervous tissue. In yetanother embodiment, the wavelength is selected to distinguish nervoustissue from muscle. Wavelength selection information andcharacterization and other details related to infrared endoscopy arefound in U.S. Pat. No. 6,178,346; US Patent Application Publication No.2005/0014995, and US Patent Application Publication No. 2005/0020914,each of which is hereby incorporated by reference in its entirety.

5. Steering Mechanisms

As mentioned previously, one or more embodiments of the retractorcannula device may be provided with any of a wide variety of steeringconfigurations, such as the steering mechanism 120 depicted in FIG. 1.In one embodiment, the retractor cannula device is steerable in one ormore axes, including a device with two axes. In some embodiments, oneaxis may be a rotation axis. In another embodiment, the retractorcannula device is non-steerable. In yet another alternative embodiment,the retractor cannula device may be pre-formed into a shape that isadapted to access a portion of the spinal region or other region of thebody. The shape may include any of a variety of angled and/or curvedsegments to access a particular body site. In yet another embodiment,the retractor cannula device is situated within the trocar in such a waythat the retractor cannula may have steering capability up to about 360°inside the spinal space. A steering mechanism, e.g., the steeringmechanism 120, may include one or more flexible bodies or the flexibleregion 124 on the retractor cannula device 100. The flexible body may bebent by manipulating a control such as the lever 122 located on thehousing 118. Various examples of the steering mechanism and the bendingregion 124 and are described in greater detail below.

B. Tubular Body

1. Flexible Region

As described previously, retractor assemblies may be coupled with atubular body, where the tubular body may be used to control thepositioning of the retractor assembly in a targeted body region. Atubular body may comprise certain features that allow the retractorcannula device to maneuver in anatomically dense regions of the body,where tissue structures tend to collapse around any instrument or deviceinserted therein, e.g., an intervertebral disc, epidural area. Retractorassemblies, for example, retractor assemblies 300 and 401 as describedabove, may be directly coupled to a tubular body, e.g., tubular body102, which may be controlled by a steering mechanism 120, as shown inFIGS. 1 and 2. As depicted there, the tubular body 102 comprises theflexible region 124. In some embodiments, a retractor assembly may bemay be coupled to tubular body 102 by a separate flexible component. Thebending range of a tubular body may vary depending upon the particulardesign. The retractor cannula device may be configured with a one-sidedor a two-sided bending range with respect to the neutral position of thetubular shaft. The bending range may be from about 0 degrees to about135 degrees, while in other embodiments, the bending range may be fromabout 0 degrees to about 90 degrees, and sometimes about 0 degrees toabout 45 degrees, and still other times about 0 degrees to about 15 orabout 20 degrees. The bending range of the other side, if any, may beless than, equal to, or greater than the first side. In someembodiments, increased bending angles may cause creasing or telescopingof the tubular shaft, which may obstruct one or more channels within thetubular shaft.

In some embodiments, to enhance the bending range of the tubular body,one or more flexion slots may be provided on the tubular body. FIG. 6depicts one embodiment of tubular body 270, comprising a plurality ofslots 272. The slots 272 may have a generally circumferentialorientation, but may alternatively have a helical orientation or otherorientation. The slots 272 may be equally or unequally spaced along thelongitudinal length of the tubular body 270. In one example, the slotsthat are located about the ends of the flexible region may be spacedfarther apart than the slots located about the middle of the flexibleregion. The slots 272 may have a similar configuration or aheterogeneous configuration. The slots 272 depicted in FIG. 6 also havea generally constant width, but in other embodiments, the width may varyalong the length of the slot. The spacing between the slots ends 274 ofa slot 272 may be substantially similar or different among the slots 272comprising the flexible region.

As noted in FIG. 6, the slot ends may comprise a rounded configuration,or any other configuration, including but not limited to an oval end,square end, triangular end, or any other polygonal shape for example. Insome embodiments, such as the example depicted in FIG. 7A, the roundedends 276 may have a larger transverse dimension than the width of therest of the slot 278. In some embodiments, a rounded end may betterdistribute the flexion stress along the edges of the slot compared tosquared or angled ends. Also, ends that are larger than the slots, suchas the enlarged rounded ends 276 in FIG. 7A, may reduce the degree ofcompression or contact between the slot edges during flexion, which mayalso reduce the risk of cracking at the slot end. FIG. 7B depicts theenlarged rounded slot ends 276 of FIG. 7A in flexion. In someembodiments, the slot end may have a more complex configuration, such asthe T-shaped slot end 280 as depicted in FIG. 8.

In some embodiments, the number of slots per slot region may be anywherefrom about 1 slot to about 100 slots or more, sometimes about 12 slotsto about 50 slots, and other times about 24 slots to about 48 slots. Insome embodiments, the length of the flexible region may be anywhere fromabout 1 inch to about 20 inches, sometimes from about 4 inches to about10 inches, and other times about 5 inches to about 8 inches in length.In some embodiments, the outer diameter of the flexible region may beabout 0.05 inches to about 0.3 inches, sometimes about 0.08 inches toabout 0.15 inches, and other times about 0.1 inches to about 0.12inches. The wall thickness of the flexible region may be in the range ofabout 0.001 inches to about 0.01 inches, sometimes about 0.002 inches toabout 0.006 inches, and other times about 0.003 inches to about 0.004inches. The slots 272 may have an average slot width in the range ofabout 0.004 inches to about 0.02 inches, some times in the range ofabout 0.005 inches to about 0.015 inches, and other times about 0.006inches to about 0.008 inches. The spacing between the slots 272 may bein the range of about 0.015 inches to about 0.1 inches, sometimes about0.020 inches to about 0.050 inches, and other times about 0.025 inchesto about 0.04 inches. The spacing between the ends of the slots may bein the range of about 0.004 inches to about 0.05 inches, sometimes about0.006 inches to about 0.02 inches, and other times about 0.004 inches toabout 0.01 inches. The maximum transverse dimension of a slot end may bein the range of about 0.004 inches to about 0.008 inches, other timesabout 0.004 inches to about 0.03 inches, and other times about 0.01inches to about 0.04 inches.

The steering and maneuvering of retractor assemblies and flexibleregions of the tubular body may be controlled using any suitablemechanism, one example of which is shown in FIGS. 9 and 10A-10C.Referring to FIG. 9, the steering mechanism 120 is configured to causebending of the tubular body 102 at one or more flexible regions 124. Asdepicted there, the steering mechanism 120 is depicted with the porttubing and a portion of the housing 118 of the retractor cannula device100 removed. The steering mechanism comprises a lever 122 that isconfigured to rotate or pivot at a lever axle 190. The lever 122 isattached to two control members 192 that are slidable located along thelength of the shaft 102 and are attached at a distal location of thetubular body 102. One or more posts 191 may be provided against thecontrol members 192. In some embodiments, the posts 191 may befacilitate changes in the orientation of the control members 192, smoothsliding of the control members 192, and/or to protect other componentsof the retractor cannula device from cutting or other damage caused bythe movement of the control members 192. In some embodiments, the endsof the control members 192 are secured to the lever 122 in one or moreretaining channels or retaining structures, but in other embodiments,the control members may be proximally attached to form a control memberloop that may be secured to a lever by placing the loop within aretaining channel of the lever. In some embodiments, one or more controlmembers 192 or the control loop may be crimped, wound, sutured and/orembedded into the lever. The movement range and force may be augmentedby one or more bias members 198 acting upon the lever 122. The biasmembers 198 may comprise helical springs as depicted in FIG. 9, but mayalso comprise leaf springs or any other type of bias memberconfiguration. The movement range of the lever 122 may also be affectedby the size and/or configuration of the lever openings 199 provided inthe housing 118. In some embodiments, an optional locking mechanism maybe provided to substantially maintain the lever in one or morepositions. The control members 192 may comprise wires, threads, ribbonsor other elongate structures. The flexibility and/or stiffness of thecontrol member 192 may vary depending upon the particular steeringmechanism. In further embodiments, the characteristics of the controlmember 192 may also vary along its length. In embodiments comprising twoor more control members, the control members need not be configuredsymmetrically, e.g. having the same length, cross-sectional area orshape, or opposite attachment sites with respect to the longitudinalaxis of the tubular shaft. Also, individual control members need nothave the same configuration along their lengths.

For example, although the proximal end of the control members 192depicted in FIG. 9 comprises wire-like members, the distal ends 250 ofthe control members 252, illustrated in FIG. 10A, comprises ribbonstructures 254. In some embodiments, the greater surface area of theribbon structures may reduce the risk of damage to the flexible region256 of a retractor cannula device. In the particular embodiment depictedin FIG. 10A, the ribbon structures 254 have a U-shaped configurationthat forms a mechanical and/or interference fit with the flexible region256 or other distal or flexible region of the tubular shaft. Theflexible region 256 may comprise one or more notches 260, recesses oropenings 262 configured to accept the ribbon structure 254. In FIG. 10A,notches 260 are provided to resist slippage of the ribbon structure 254along the lip 264 of the flexible region 256, while the openings 262 areprovided to permit insertion of the ribbon ends 264 to further augmentthe interfit of the ribbon structures 254 and the flexible region 256.FIG. 10B illustrates another embodiment where in the ribbon structure266 inserts through the opening 262. In this particular embodiment, theribbon structure 266 may also be welded or soldered back onto itself toform a loop to further secure the ribbon structure 266 to the flexibleregion 256. In other embodiments, as depicted in FIG. 10C, the tip 269of the ribbon structure 268 may be bonded or soldered to the flexibleregion 256 or the tubular shaft, depending upon the material of theribbon structures and the flexible region or the tubular shaft.

In some embodiments, during bending, one or more components insertedthrough the one or more channels in the tubular body of the retractorcannula device may exhibit different degrees of relative displacement.The degree of relative displacement may be affected by the degree ofbending, the fixation or coupling site, if any between the component andthe retractor cannula device, and/or the degree of displacement from theneutral position of the retractor cannula device. Referring to FIG. 11A,a retractor assembly 1116 of retractor cannula device 1100 shown inneutral position (e.g. straight, but may be angled or curved in otherembodiments) with an endoscope 282 located in the visualization channel128. The tip 284 of the endoscope 282 is in proximity to the end 286 ofthe visualization channel 128. As the retractor cannula device 1100 isflexed as shown in FIG. 11B, the tip 284 of the endoscope 282 mayexhibit a relative distal displacement with respect to the end 286 ofthe visualization channel 128, particularly in embodiments where theendoscope 282 is coupled to the retractor cannula device 100 at aproximal location (e.g. about the housing). When the retractor cannuladevice 100 is flexed in the opposite direction, in some instances theendoscope 282 may exhibit a proximal retraction. To compensate for thedisplacement, the user may manually adjust the position of the endoscope282 as desired.

In some embodiments, the steering mechanism may also be coupled to anendoscope adjustment mechanism so that manipulation of the steeringmechanism also provides at least some position adjustment which mayreduce if not eliminate the degree of displacement. In otherembodiments, the endoscope may be coupled to the retractor cannuladevice about a distal region of the tubular body so that, duringflexion, the proximal portions of the endoscope exhibit the displacementrather than the distal portions. In still other embodiments, a spring orother type of bias member may bias the endoscope distally against aninterference structure (not shown) located at the distal end of thetubular body to maintain the endoscope position during flexion. In somefurther embodiments, the interference structure may be rotated or movedout of its interfering position to permit endoscope positioning moredistally, as desired.

2. Lumens and Channels

As described previously, one or more lumens or channels may be providedin the tubular body of a retractor cannula device. Lumens and/orchannels may be used for the delivery of devices and therapeutic agentsfor a variety of functions, for example, visualization, dissection,dilation, displacement, aspiration, irrigation, infusion of medications,augmentation of tissue such as a disc, decompression of tissue such as adisc nucleus, ablation, stimulation, implantation of devices, and anyother desired function. One embodiment, which is depicted in FIGS. 12Aand 12B, for example, the tubular body 102 is depicted without theretractor elements to show the two channels, e.g., the visualizationchannel 128 and the channel 130 that open at the distal end 106 of thetubular body 102. In other embodiments, however, the tubular body maycontain a different number of channels or channels with differentpositions, cross-sectional areas, or cross-sectional shapes, as shown inthe examples in FIGS. 13A-13C and 14. Referring to FIGS. 12A and 12B,the visualization channel 128 may be used to deliver imaging devices,e.g., as an endoscopy channel, while the channel 130 may be used as aworking channel for insertion of one or more instruments. Also shown islumen 132, which may enclose at least a portion of the lumen of thetubular body 102, and may enclose at least a portion of thevisualization channel 128 and the channel 130. One or more channels mayhave a longitudinal length that substantially spans the length of thetubular body 102, but other channels may have a length shorter than thetubular body 102, and may terminate proximal to the distal end 106.Other channels may also be used, for example, to control bending orother movements of the cannula device. One or more channels may comprisea layer or coating to facilitate sliding of instruments within thechannel, including PTFE and any of a variety of biocompatible lubriciouscoating materials. In some embodiments, the shaft may comprise a rigidor semi-rigid material, but in other embodiments, may comprise aflexible material.

Proximally, one or more of the channels 128, 130 and 132 of the tubularbody 102 may be in communication with one or more ports 108, 110, 112and 114. In the embodiment depicted in FIG. 1, for example, thevisualization channel 128 of the retractor cannula device 100 may be incommunication with the port 114, which may be configured to interfacewith an endoscope and act as an endoscopic port. Alternatively oradditionally, the channel 130 may also be in communication with the port112, which may be configured for the insertion and delivery ofinstrumentation, and channel 132 may be in communication with the port108, which may be configured to be an irrigation or aspiration port. Insome embodiments, a separate irrigation port and aspiration port may beprovided, which may permit simultaneous infusion and aspiration.Simultaneous infusion and aspiration may expedite clearing of theworking field when compared to alternating infusion and aspiration usinga single channel.

In some embodiments, the visualization channel 128 may be provided,where the visualization channel may be augmented by changes to thegeometry and/or movement of the retractor assembly 116. For example,some retractor assemblies may have hinge mechanisms that allow theretractor elements or jaws to form an angle greater than about 90degrees or greater than about 180 degrees. In other examples, retractorassemblies may have different longitudinal lengths relative to theirarticulation points. For example, some retractor assemblies may have aretraction element with a length of at least about 1 mm, about 2 mm,about 3 mm, about 4 mm, about 5 mm, about 6 mm or more from itsarticulation point with the shaft. The longitudinal lengths of eachretractor element may be the same or different. The retractor cannuladevice used may be selected depending upon the region of the body inwhich the retractor cannula device has been deployed. In regions withlarge cavities, a rounded shape retractor assembly may be used to reducethe trauma to surrounding tissue without compromising the field of view.In regions where tissue is more densely compacted or folded, a taperedshape retractor assembly may be used because the taper of the closedconfiguration would allow it to maneuver into folds, and upontransitioning into the open configuration, substantially dilate thetissue to allow for a larger field of view and working space. In otherexamples, multiple retractor cannula devices with differentconfigurations may be used during at the same target site.

Referring to FIGS. 12A and 12B, the visualization channel 128 may beused as a passage for insertion/removal of illumination, visualization,and/or imaging components to provide direct visualization capabilitiesat the distal end 106 of the retractor cannula device 100. In someembodiments, a visualization channel 128 may house or may be integrallyformed with one or more illumination, visualization, analytical, and/orimaging components, including but not limited to one or more fiber-opticstrands used to transmit light from a light source or to opticallyvisualize the anatomy about the distal end 106 of tubular body 102.

The visualization channel 128 or the distal end 106 of the device 100may include a sensor used to generate images or identify tissue ortissue characteristics. In one example, the sensor utilizes acousticenergy to generate the image, similar to diagnostic ultrasound. Inanother example, the sensor utilizes an electrical characteristic togenerate the image or other types of structural or physiologicalinformation. In yet another example, the sensor distinguishes the typeof tissue adjacent to the sensor. Some properties used by the sensor todifferentiate adjacent structures or tissue include resistance,capacitance, impedance, membrane voltage, acoustic, and opticalcharacteristic of tissue adjacent the sensor or probe. Additionally, thesensor or image may be used to distinguish different types of tissue toidentify neurological tissue, collagen, or portions of the annulus, forexample. It is to be appreciated that the sensor may be a multi-modal ormulti-sensor probe that can distinguish bone, muscle, nerve tissue, fat,etc. to help position the probe in the proper place.

FIGS. 13A to 13C illustrate various embodiments of the retractor cannuladevice, where different tubular bodies may have different numbers,sizes, and shapes of lumens or channels therethrough. In FIG. 13A, theretractor cannula device 1300 may comprise a tubular body 1302 with anon-circular channel 1328 configured to house a visualization device(such as, but not limited to, an endoscope), a non-circular workingchannel 1326 which may be used to provide therapy device or asaspiration port, a retractor assembly actuator lumen 1332, andadditional port 1330 for irrigation or aspiration. The tubular body 1302may also optionally comprise one or more structures 1362 on its outersurface 1364. These structures 1362 may comprise recessed or protrudingconfigurations and may be used, for example, to maintain alignment withrespect to introducer or guide member, or to reduce the amount offrictional resistance from any manipulation of the retractor cannuladevice 1300. As depicted in FIG. 13B, the tubular body 1366 of theretractor cannula device 1368 may have a non-circular visualization orirrigation port 1370, a circular therapy device or aspiration port 1372,a circular retractor assembly actuator lumen 1374, and additionalcircular port 1376 for additional irrigation or additional aspirationhaving a greater. As demonstrated in FIG. 13B, the circular ports 1372,1374 and 1376 need not have the same diameter. In FIG. 13C, the tubularbody 1378 of the retractor cannula device 1380 has a visualization orirrigation port 1382, an injection port or therapy device or aspirationport 1384, and a retractor assembly actuator lumen 1386, wherein no portor lumen has a circular cross-sectional shape. It is contemplated thatfunctions of various lumens in a cannula device may be suitablyinterchanged.

Referring back to FIG. 13A, the tubular body of the retractor cannuladevice 100 may include a visualization channel 1328, a larger workingchannel 1326, and an additional irrigation/aspiration port 1330. Thechannels and/or ports of the retractor cannula device 1300 may beconfigured to accept wide variety of therapy devices suited to the typeof therapy being performed. The therapy device may be configured andused to apply energy to surrounding tissue. The therapy device may alsobe a surgical instrument used to cut, pierce or remove tissue. Moreover,it is to be appreciated that the therapy device may be any conventionalendoscopic instrument. The therapy device may include ultrasonicdevices, motor driven devices, laser-based devices, RF energy devices,thermal energy devices, cryotherapy-based devices, or other devicesselected based on the spinal therapy being performed. For example, thetherapy device may also be a mechanical device adapted to remove tissuesuch as a debrider or an aspirator. Other examples are described ingreater detail below. Moreover, it is to be appreciated that theretractor cannula device 1300 may be used to inject pharmacologicalagents into the spinal area. The size, number and arrangement of theworking channels are readily adaptable for different configurations,depending upon the type of procedures performed. A greater or a fewernumber of working channels may be provided, and the working channelsneed not have the same size and shape. In addition, the working channelsmay also be configured to perform auxiliary functions. In one examplethe channels or ports may be used to provide irrigation to assist intissue dissection as the atraumatic tip is advanced in the spinal space.An irrigating working channel may be in communication proximally with afluid source, such as a syringe or intravenous infusion system, and incommunication distally with the distal end of the retractor cannuladevice so that the fluid exiting the irrigation working channel isdirected to the distal portion of the retractor cannula device. Inanother example, the irrigation working channel or another workingchannel may be used to rinse the atraumatic tip or keep clear otherportions of the retractor cannula tool. In the particular embodimentdepicted in FIG. 13A, the working channel 1326 and the visualizationchannel 1328 are configured with non-circular cross-sectional shapes. Insome embodiments, the non-circular shape permits the placement of aninstrument with a circular cross-sectional shape within the channel orport while providing still providing flow paths for fluids and materialthrough the channel 126 and the visualization channel 1328. Shared oreccentric flow paths along non-circular shaft channels and ports mayalso otherwise take advantage of unused sections of the cannula shaft.Unlike shafts with only circular channels or ports, the flow paths maybe provided without having to increase the overall cross-sectional areaof the cannula shaft. Channels or ports having non-circularcross-sectional shapes may also be used with instruments having acomplementary non-circular cross-sectional shape. For example,complementary non-circular cross-sectional shapes may be used to controlor limit the amount of instrumentation rotation within the channel orport.

FIG. 14 is a schematic representation of a tubular body 320 of oneembodiment of a cannula device 322 configured for two-sided flexionwithin a bending plane. In some embodiments, one or more channels of thetubular shaft 320 may be configured and positioned to reduce the degreeof endoscope or instrument displacement during flexion. In FIG. 15, forexample, the tubular shaft 320 comprises a visualization channel 324 anda working channel 326 wherein the centers 328 and 330 of the channels324 and 326, respectively, are located along a plane 332 that isperpendicular to a bending plane 334 of the cannula device 322. Plane332 may be located, for example, between the midpoint of the two distalattachments of the steering mechanism. The relative position of theplane 332 and the bending plane 334 may vary depending upon theparticular manner in which the steering mechanism is anchored to theflexion region. In other embodiments, the centers 328 and 330 need notbe located on the plane 332, but the central location of the optics orworking instruments inserted into the channels 324 and 326 are locatedon the plane 332. For example, a channel may be configured such that theoptical center of an endoscope is substantially aligned with the plane332, even through the weighted center of the channel and/or endoscopemay not be located on the plane 332 (e.g. where the lens of theendoscope is asymmetrically located, or where the central viewing angleIn embodiments comprising circular channels, the center of the channelmay be the center of the circle. In other embodiments comprisingnon-circular channels, the center of a channel may be characterized asbeing coaxial with the center of the largest circular object that may beinserted into the channel.

Although the embodiment shown in FIG. 15 is directed to a cannula devicehaving a single bending plane, in other embodiments, the cannula devicemay be configured with two or more bending planes. With these latterembodiments, one or more channels may be aligned with one bending planebut not another bending plane. In some embodiments, a central channelmay be provided that is aligned with two or more bending planes.

In some embodiments, a trocar may be guided using fluoroscopic or otherexternal imaging modality to place the trocar in proximity to atreatment area. In contrast to conventional procedures that attempt tofluoroscopically navigate a trocar tip around nerves and other tissue,the trocar may remain safely positioned away from sensitive structuresand features. In one embodiment, the trocar tip remains about 1 to about2 cm or more from vulnerable nerve tissue. In another embodiment, thelast about 1 to about 2 cm of travel to a therapy site is performedusing direct visualization provided by a visualization mechanism in theretractor cannula device.

In some embodiments, the trocar is removed and the retractor cannuladevice 100 is inserted into the pathway formed by the trocar. In otherembodiments, a tubular trocar may be used. From the final trocarposition, the retractor cannula device 100 may be passed through achannel or lumen of the trocar and along the remaining distance to thetherapy or treatment site using the onboard visualization capabilities.The onboard visualization may be used alone or in combination with theretractor assembly 116 or other type of atraumatic tip to identify,atraumatically displace, and/or maneuver around nerves and other tissueas needed. An optional steering mechanism may be provided on theretractor cannula device 100 to manipulate surrounding tissue andstructures, and/or to traverse the remaining distance to one or moretherapy or treatment sites. In other embodiments, the retractor cannuladevice 100 may have a rigid or fixed configuration, and may bemanipulated by optionally manipulating the trocar to reach a desiredlocation. In an alternative embodiment, the trocar may house theretractor cannula device during trocar insertion and thus utilize thedirect visualization capabilities of the visualization mechanism withinthe retractor cannula device to guide trocar positioning. In stillanother embodiment, the trocar may be provided with a separate imagingsystem from the imaging device or component provided in the retractorcannula device for use during trocar insertion. In still anotherembodiment, the trocar may be configured with a lumen to house only theimaging component from the retractor cannula device 100. After thedesired trocar position is reached, the trocar is removed and theimaging component is removed from the trocar and reinserted into theretractor cannula device 100. In yet another alternative embodiment,both external imaging may be used to position the trocar distal end,either alone or in combination with direct imaging.

2. Handle Portion

As described previously, a retractor cannula device may be provided witha handle, e.g., handle 118, to control the navigation and use of thetubular body and retractor assembly. The handle may also serve as aninterface between a variety of functional ports and the longitudinalchannels and/or lumens of the tubular body, where the channels andlumens of the tubular body may be continuous with lumens and channels ofthe retractor assembly. Referring now to FIG. 16, the proximal end 360of the tubular body 362 may be coupled to one or more tubing segments364, 366, 368, 370, 372 that correspond to one or more channels andconnectors 374, 376, 378, 380, and 382 of the retractor cannula device1600, respectively. As noted in FIG. 16, a tubing segment 370 may be incommunication with another tubing segment, such as the tubing segment368, which connected to the working channel of the device 382. Thisparticular tubing segment 370 may be used, for example, to flush oraspirate fluid or material inserted into the working channel of thedevice 382 that is accessed through the middle port 378 and tubingsegment 368. The particular design features of a tubing segment mayvary, depending upon the particular function. The connector coupled to aparticular tubing segment may comprise any of a variety of connectors orinstrument interfaces. In some embodiments, for example, one or moreconnectors may comprise a standardized connector such as Luer lock,while in other embodiments, the connector may be a proprietaryconnectors. Depending upon the particular channel, in some embodiments,a check valve, septum, or a hemostasis valve may be provided to resistretrograde flow of fluid out of the device. The characteristics of aparticular channel, including its dimensions and flexibility orrigidity, may depend upon its particular use. In FIG. 17, for example, aretractor cannula device 1700 comprises five ports 386, 388, 390, 392and 394, wherein the longer, flexible ports 388 and 392 may be used forinfusion or aspiration. Such ports may be beneficial to facilitate theattachment of a bulky item such as a syringe. A rigid port, such as port390, may be provided for instruments that may otherwise be damaged orare difficult to pass through tubing that may exhibit greater frictionalresistance.

The therapy device may be supplied with energy from a source externalusing a suitable transmission mode. For example, laser energy may begenerated external to the body and then transmitted by optical fibersfor delivery via an appropriate therapy device. Alternately, the therapydevice may generate or convert energy at the therapy site, for exampleelectric current from an external source carried to a resistive heatingelement within the therapy device. If energy is supplied to the therapydevice, transmission of energy may be through any energy transmissionmeans, such as wire, lumen, thermal conductor, or fiber-optic strand.Additionally, the therapy device may deliver electromagnetic energy,including but not limited to radio waves, microwaves, infrared light,visible light, and ultraviolet light. The electromagnetic energy may bein incoherent or laser form. The energy in laser form may be collimatedor defocused. The energy delivered to a disc may also be electriccurrent, ultrasound waves, or thermal energy from a heating element.Moreover, it is to be appreciated that embodiments of the retractorcannula devices described herein may also be used to dispense acompound, compounds or other pharmacological agents to reduce, diminishor minimize epidural neural tissue scarring.

As noted in the embodiment depicted in FIG. 1, the visualization channel128 provides access to the target area for endoscopic imaging and/ormedical imaging components. The retractor elements of a retractorassembly in the open configuration may act as dilators or retractors topermit a wider field of view. For example, the retractor cannula devicemay first assume a closed configuration in order to atraumaticallynavigate towards the target body region. Once the distal end of theshaft has reached the target area, a retractor assembly can betransitioned to the open configuration, dilating the surrounding tissueand enabling an endoscope positioned in visualization channel 128 tovisually access the target tissue. In some embodiments, the retractorelements of the retractor assembly may be made of a transparentmaterial, so that even in the closed configuration, the endoscoperesiding in visualization channel 128 may have visual access to thesurrounding tissue, and may allow the endoscope to be used to providevisual cues to navigate the distal tip of the cannula to the desiredlocation.

As mentioned previously, an endoscope or working instrument (e.g.grasper(s), balloon(s) or tissue debrider) may be inserted into one ormore channels of the cannula device through a proximal port. Theproximal port, endoscope, and/or working instrument may be optionallyconfigured with one or more features to lock and/or adjust the positionof the inserted component. In other embodiments, one or more componentsof the endoscope or working instrument may be an integrally formedcomponent of the cannula device and is not configured for removal.

For example, in FIGS. 18A and 18B, a retractor cannula device 340 isconfigured with a scope port 342 in communication with the visualizationchannel (not shown) with a segment of tubing 344. The scope port 342 maycomprise a lumen with a viscoelastic or friction surface material thatis configured to slidably grip an inserted endoscope. The slidablygrippable materials may include but are not limited to silicone, aurethane, including viscoelastic urethanes such as SORBOTHANE® (Kent,Ohio) and any of a variety of styrenic block copolymers such as somemade by KRATON® Polymers (Houston, Tex.). The scope port 342 thus neednot have any particular clamp or locking mechanism to secure theendoscope or working instrument to the scope port 243, nor anyparticular adjustment mechanism. In other embodiments, however, thescope port may comprise a releasable lock or clamp mechanism designed tocouple to the endoscope or working instrument, with an optionaladjustment assembly that may be used to modify the spacing between thelock or clamp mechanism and the housing.

Another variation of a handle that may be used with the devices andmethods described above is shown in FIGS. 23A and 23B. FIG. 23A is aside-view of the handle 2118, which may comprise a housing 2120 which isshaped and sized to accommodate various ports and actuators aspreviously described. For example, the housing 2120 may have aperturesto accommodate the handle port 2123, and optionally, the auxiliary port2130. The auxiliary port 2130 as shown in FIGS. 23A and 23B retains atube 2130, but in other variations, may retain a plug or valve. Forexample, where the auxiliary port 2130 is used as a saline flush port,the tube 2130 may be sized to fit with other valves or tubes connectedto a saline reservoir. When not in use, the auxiliary port 2128 may beoccluded with a plug, which may help to prevent accidental insertion offluids or devices. The handle port 2123, depicted in FIG. 23B, may beconfigured to accommodate any of the previously described devices, forexample, a visualization device (e.g., an endoscope), or othertissue-manipulating devices (e.g., for extracting or dissecting tissue).One or both the handle port 2123 and the auxiliary port 2128 may be incommunication with one or more lumens in the tubular body 2102. Devicesmay be coupled to the handle 2118 by the device coupler 2122, which maybe a pin, screw, clip, etc. that is configured to secure a device to thehandle 2118. The device coupler 2122 may also secure a device byfriction-fit, form-fit, snap-fit, bonding by adhesives or Velcro™, andthe like.

The handle 2118 may also have any number and type of actuators forcontrolling the navigation of the tubular body 2102, as well as forcontrolling the configuration of the retractor assembly attached at thedistal end of the tubular body. For example, the pivot lever 2124 may beused to transition the retractor assembly associated with handle 2118(e.g., any of the retractor assemblies described previously may be usedhere) from a closed to an open configuration. A resistance pin 2126 maybe included to regulate the actuation force of the pivot lever 2124.Optionally, the bias spring 2132 may be coupled with the pivot lever2124 to bias it into one configuration, for example, the closedconfiguration. The length, spring constant, and other features of thebias spring 2132 may be selected to bias the pivot lever 2124 (and inturn, bias the retractor assembly) into any configuration as desired.The pivot lever lock 2125 may also be included to restrict the actuationof the pivot lever 2124. As with the handles described previously, anynumber of ports, tubes, and actuators may be included according to thedifferent devices that may be used during various procedures on a body.

C. Methods

A retractor cannula device may be used for a variety of functions, whichmay be performed in a variety of procedures on a body. A retractorcannula device may be used for visualization, dissection, dilation,displacement, aspiration, irrigation, infusion of medications,augmentation of tissue such as a disc, decompression of tissue such as adisc nucleus, ablation, stimulation, implantation of devices, and anyother desired function. Such a device may be used in medical proceduressuch as tissue biopsy, disc augmentation, nucleus decompression, nucleusabrasion, as well as for the repair of a herniated disc, and for thediagnosis of disc degeneration. Other procedures, such as theimplantation of devices to structurally support a disc annulus, or toshrink a portion of the nucleus or annulus, or sealing an annulus, mayuse one or more of the devices and components described above.

During use, the retractor cannula device may be moved or may remain inplace while an inserted therapy device is manipulated to perform thedesired function. Once the working or therapy area has been created oraccessed using the atraumatic retractor assembly, the atraumaticretractor assembly may be removed thereby allowing working channel ortrocar or introducer to be used for another instrument or therapy deviceor to provide support for a procedure. For example, the therapy devicemay comprise a mechanical debrider or other type of tissue disruptingdevice that may be introduced via the working channel to assist inremoval of tissue. Various examples of mechanical tissue disruptingdevices that may be used with a retractor cannula device are describedin U.S. patent Ser. No. 12/035,323, filed Feb. 21, 2008, which waspreviously by incorporated by reference in its entirety. In yet anotherexample of the flexibility of the retractor cannula device, one or morethe working channels or ports may be used to provide access for thedelivery of pharmacological agents to the access site either forapplication onto or injection into tissue. In some embodiments, thetherapeutic agents may be directed injected into the channel or port,but in other embodiments, an infusion catheter may be inserted into achannel or port and used to provide additional control of the therapy.The infusion catheter may have any of a variety of configurations andfeatures, including but not limited to its own optional steeringmechanism separate from the retractor cannula device, and a needle tipfor injecting therapeutic agents into the tissues or structures. In someembodiments, the needle tip may be retractable and extendable to protectagainst inadvertent puncture of the tissues or structures accessiblefrom the retractor cannula device. Examples of injection catheters thatmay be used with embodiments of the retractor cannula device includeU.S. patent Ser. No. 10/820,183, which is hereby incorporated byreference in its entirety.

The flexion of the retractor cannula device may facilitate access to thetarget site and/or reduce the degree of tissue disruption in achievingaccess to the target site. For example, in some procedures, the anglefor approaching the target site through the skin may be different fromthe angle that provides the visibility or viewing angle to treat ordiagnose a particular abnormality. Referring to FIG. 19, in someembodiments, a cannula system 340 may be inserted to a target site 342by utilizing longer or indirect access pathways 344 in order to achievethe desired approach angle to a target site, and/or to avoidinterference from structures such as the transverse spinal processes346. By using a steerable cannula system 348 as depicted in FIG. 20,however, a shorter or a more direct insertion pathway 350 may be takento a target site 352, which may reduce the aggregate degree of tissuedisruption compared to a longer insertion pathway. By taking advantageof the steerability of the cannula system 348, the desired approachangle to a target site may be achieved.

The retractor cannula device may also be used to perform denervationprocedures using direct visualization from the retractor cannula device.The denervation procedure may be physical, chemical or electricaldenervation, for example. The approaches used may be similar thosedescribed herein to access the posterior or posterolateral annulus. Itis to be appreciated that the denervation procedures may be performed torelieve discogenic pain and/or before the disc damage has progressed toa herniated disc or torn annulus.

The retractor cannula devices may be used, for example, in systems fortreating disc degeneration that include nucleus decompression devices.The retractor cannula device may be used for accessing the nucleus anddelivering a nucleus decompression device. For example, a decompressiondevice may be advanced from one of the working channels of the retractorcannula device and into the nucleus of a disc. A nucleus decompressiondevice may be used to removed the disc nucleus tissue either bydissection, suction, dissolving, or by shrinking the nucleus. Varioustypes of thermal energy are known to shrink the nucleus such asresistive heat, radiofrequency, coherent and incoherent light,microwave, ultrasound or liquid thermal jet energies. Mechanical tissueremoval devices may also be used. Decompression of the disc nucleus mayresult in the protruded disc material collapsing toward the center ofthe disc. This may reduce the pressure on the spine nerve roots, therebyminimizing or reducing the associated pain, weakness and/or numbness inthe lower extremities, upper extremities, or neck region. One or moredevices that may be used to strengthen and/or support the weakened discwall may also be used with a retractor cannula device.

In addition to spinal applications, the atraumatic cannula system mayalso be used for a variety of other procedures. The atraumatic cannulasystem, including the retractor cannula systems, may be used to providedirect visualization to a variety of both bedside and surgicalprocedures that were previously performed blind and/or with indirectvisualization. Such procedures include but are not limited to pleuralbiopsy, pleuracentesis, paracentesis, renal biopsy, and jointaspiration, for example. In another example, the cannula system may beused in the emergency room or trauma centers to perform peritoneal tapsto diagnosis blunt abdominal trauma.

In some embodiments, the retractor cannula device may be used fordiagnostic purposes. Because of the complexity of the spine, it may bemore difficult to diagnose an injury than for other medical conditions.As such, the direct visualization capabilities of the subject devicesmay be able to accurately identify any instability or deformity in thespine. For example, the subject device may offer direct visualization ofany tumors, fractures, nerve damage, or disc degeneration. In addition,the subject devices may include sensors for collecting diagnostic data,for example, sensors that measure flow, temperature, pressure, or oxygenconcentration. The subject devices may also be used to remove fluid,tissue or bone samples to be used for external diagnostic tests.Additionally, the subject devices may deliver testing reagents oradditional instruments for diagnosing disc degeneration and bonydegeneration, for example, the subject devices may deliver electrodesfor diagnosis and treatment.

In one embodiment, the retractor cannula device may be used to performdiscectomy. In this particular embodiment, the patient is prepped anddraped in usual sterile fashion and in a lateral decubitis or proneposition. General, regional, or local anesthesia is achieved and a rigidguidewire may be inserted percutaneously to the epidural space.Guidewire placement may be performed under fluoroscopic guidance orother types of indirect visualization including ultrasound. In someinstances, a small skin puncture or incision is made about 2 to 5 inchesfrom the midline of the patient's lumbar region to facilitate guidewireinsertion. A needle may also be used to facilitate guidewire passagethrough some tissues. The guidewire may introduced on the ipsilateralside from which the nerve impingement has been identified and at anangle of about 25 degrees to about 45 degrees to the patient's back, butin other procedures, a contralateral approach and/or a different anglemay be used. After confirmation of the guidewire location, a dilator mayor may not be inserted over the guidewire to enlarge the guidewire pathto the epidural space. An introducer with a releasable lock may beinserted over the dilator to maintain access so that the dilator andguidewire may be removed. An endoscope or other type of directvisualization may be inserted into the scope channel of the retractorcannula device. An irrigation fluid source is connected to theirrigation port on the retractor cannula and activated to providecontinuous flushing. A passive or active aspiration port or outlet portis checked for patency. The retractor cannula is inserted into theintroducer and advanced toward the epidural space. Direct visualizationof the epidural space may be performed with the endoscope as theretractor cannula nears the epidural space. As the retractor cannulaenters the epidural space, the retractor assembly may be manipulated(e.g. flexed and/or rotated) to orient the user and to identify thespinal nerve and for any disc or foraminal pathology. The retractorcannula device may then be advanced closer to the treatment site. Wherethe treatment site is abutting or impinging upon a nerve, the retractorassembly in the open configuration may be used to separate the treatmentsite and the nerve and to create a working space at the treatment site.In some embodiments, a guidewire may be reinserted into a channel of theretractor cannula and advanced past the tip of the retractor assemblytoward the treatment site. For example, the guidewire may be insertedinto a bulging region of the annular wall at the site of impingement.Insertion may occur before or after the retractor assembly is urged intothe open configuration, and before or after a nerve is separated from abulging disc surface. Under visual guidance, the open jaws of theretractor assembly may be directed towards the tissue to be removed, andthen urged to the closed configuration, thus grasping the tissue.Appropriate maneuvering techniques may then be applied to remove thetissue gripped by the jaws of the retractor assembly. Alternatively oradditionally, a tissue disrupting instrument may be inserted in theretractor cannula device and activated to mince or disrupt the tissue atthe treatment site. For example, the retractor cannula device may beconfigured to house an automated auger, which can be turned on to spinwithin the chamber space enclosed by the retractor assembly to quicklyremove tissue. Alternatively or additionally, negative pressure may beapplied through the auger to draw the tissue targeted for removal intothe working channel. The disrupted material may be swept away by thecontinuous irrigation and flush system, or may be removed from thetreatment site by an aspiration assembly on the tissue disruptinginstrument, or secured by the jaws of the retractor assembly which isthen withdrawn distally. A coagulation probe, if needed, may be insertedinto the retractor cannula to achieve hemostasis and/or to shrinktissue. In some embodiments, the treated disc surface may self-seal dueto the small size of the tissue disrupting instrument and/or the reducedpressure in that portion of the disc following removal of disc material.In other embodiments, the treated disc may be further treated to reduceany extrusion of disc material from the treatment site. A forceps oradditional grasper instruments may also be used with the retractorcannula device to remove any extra-discal fragments. In some instanceswhere fragments may have migrated through a foramen of the vertebrae,the size of the retractor cannula may permit advancement of theretractor cannula into or even through the foramen. Thus, the retractorcannula device may be inserted into the central spinal canal from theforamen to retrieve any migrated fragments.

In another embodiment, a retractor cannula system may be utilized forany of a variety of cardiothoracic procedures, including but not limitedto bronchoscopy, pleural biopsy, pleuracentesis pericardiocentesis, andpericardial biopsy. Pericardial biopsy, for example, is indicated forthe investigation of a pericardial effusion. The procedure may beperformed under fluoroscopic guidance or using endoscopic instruments,but is still associated with substantial morbidity, including but notlimited to risks of a pneumothorax and myocardial rupture. A minimallyinvasive, direct visualization alternative may improve the risk/benefitprofile of the procedure. In one particular embodiment, the patient isprepped and draped in usual sterile fashion. Local anesthesia isachieved in the subxiphoid region of the patient. In other embodiments,other entry points into the thoracic cavity may be used instead. Inother embodiments, regional or general anesthesia may be used instead.In some embodiments where a pericardial drainage catheter was already inplace, the guidewire may be inserted into the catheter and the cathetermay be removed, leaving the guidewire in place. The guidewire may be astraight guidewire or a J-tip guidewire, for example. In embodimentswhere an initial entry into the pericardial space is made by theguidewire, a catheter may be inserted over the guidewire and one or morepericardial fluid samples may be taken for chemistry, histology, and/orculture, for example, before continuing the procedure. One or moredilators may be inserted over the guidewire and removed to widen thetissue pathway from the skin to the pericardial space. After wideningthe guidewire pathway, the retractor cannula system may be inserted overthe guidewire. In some embodiments, as the retractor cannula system isinserted, a sampling of the parietal pericardial tissue (i.e. the outerpericardial surface) may be taken before or after the placement of theretractor cannula system into the pericardial space. In someembodiments, the retractor assembly may be in the open configuration andpressed against the parietal pericardial surface. An additionalretractor assembly may be used to take one or more tissue biopsies ofthe parietal pericardial surface. A coagulation probe may be used toprovide hemostasis following the biopsy or biopsies. The retractorcannula may be placed in the closed configuration and advanced distallyover the guidewire toward the pericardial space. Once in the pericardialspace, the guidewire is optionally removed from the retractor cannulasystem. The pericardial fluid may be drained and replaced with saline ora gas to facilitate viewing. In patients with a hemorrhagic effusion,additional irrigation and/or drainage may be used to improve the clarityof the viewing field. The retractor assembly may be placed in the openconfiguration and the pericardial space may be explored by flexingand/or rotating the retractor cannula device. In some embodiments, theretractor cannula may be flexed in a retrograde fashion and the extendedretractor assembly tip of the retractor cannula is used toatraumatically tent up the pericardial tissue to reduce the tissuelaxity and increase the success of the biopsy. Unlike traditionalendoscopic procedures, which are sometimes contraindicated when there isinsufficient fluid or loculated fluid in the pericardial sac, use of thetapered shape retractor cannula system may facilitate tissue separationbetween the pericardium and the epicardium to safely perform the biopsyin those situations. Tissue biopsies of the visceral pericardium and/orthe epicardium may be taken using graspers or other endoscopic biopsytools. Using a tissue debrider and/or a coagulation probe, one or morewindows or fenestrations may be formed in the pericardium to provideongoing drainage of the pericardial effusion. Pericardial windows orfenestrations, if any, may be performed before or after entry into thepericardial space. The retractor cannula may then be removed and anx-ray may be taken to check for a pneumothorax. If needed, chest tubedrainage may be provided until the pneumothorax has resolved.

In another embodiment, the retractor cannula system may be used toperform any of a variety of genitourinary and OB/GYN procedures,including but not limited to cystoscopy (with or without bladderbiopsy), renal biopsy, prostate biopsy and surgery, fetoscopy (includingoptional fetal blood draws), and bladder neck suspension procedures. Inone particular example, cystoscopy may be performed using a flexibleretractor cannula system with a forward-positioned extendable retractorassembly, but in other embodiments, a rigid retractor cannula system mayalso be used. In one embodiment, a cystoscopy procedure may be performedby draping a patient in the usual fashion and prepping the urethralorifice with a sterilizing agent and a topical anesthetic. In patientswhere ureteroscopy may be performed in addition to cystoscopy, regionalor general anesthesia may be used instead. A topical anesthetic isoptionally applied to the exterior of the retractor cannula system asthe retractor cannula system is inserted into the urethral orifice andadvanced to the bladder cavity. In some embodiments, the bladder may befilled with a gas or a liquid to expand the bladder wall for viewing.Once in the bladder, the retractor cannula system may be flexed androtated to view the bladder cavity. Biopsies may be taken as indicatedby inserting a biopsy instrument (e.g. a grasper) into a channel of theretractor cannula device, actuating the biopsy instrument andwithdrawing the biopsy instrument. The ureteral orifice may beidentified and the retractor cannula may be inserted into the ureter. Aguidewire may be optionally inserted through the retractor cannulasystem and into the ureteral orifice to facilitate passage of theretractor cannula system into the ureter. In some embodiments, theretractor assembly of the retractor cannula system may be at leastpartially expanded during entry and/or advancement of the device, toreduce the risk of ureteral perforation. Depending upon the length ofthe retractor cannula system, the retractor cannula system may also beadvanced into the intrarenal collecting system. If a stone isencountered during the procedure, the jaws of the retractor assembly maybe actuated to remove the stone. Alternatively or additionally, a basketor other type of capturing instrument may also be inserted into theretractor cannula system to remove the stone. For stones that are toolarge to be withdrawn through a channel of the retractor cannula system,a burr or other type of disrupting structure may be used to break up thestone. Once the biopsies and/or stone break-up or removal is completed,the retractor cannula system may be withdrawn.

It is to be understood that this invention is not limited to particularexemplary embodiments described, as such may, of course, vary. It isalso to be understood that the terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto be limiting, since the scope of the present invention will be limitedonly by the appended claims.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimits of that range is also specifically disclosed. Each smaller rangebetween any stated value or intervening value in a stated range and anyother stated or intervening value in that stated range is encompassedwithin the invention. The upper and lower limits of these smaller rangesmay independently be included or excluded in the range, and each rangewhere either, neither or both limits are included in the smaller rangesis also encompassed within the invention, subject to any specificallyexcluded limit in the stated range. Where the stated range includes oneor both of the limits, ranges excluding either or both of those includedlimits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the present invention, some potential andpreferred methods and materials are now described. All publicationsmentioned herein are incorporated herein by reference to disclose anddescribe the methods and/or materials in connection with which thepublications are cited. It is understood that the present disclosuresupersedes any disclosure of an incorporated publication to the extentthere is a contradiction.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural referents unless thecontext clearly dictates otherwise. Thus, for example, reference to “ablade” includes a plurality of such blades and reference to “the energysource” includes reference to one or more sources of energy andequivalents thereof known to those skilled in the art, and so forth.

The publications discussed herein are provided solely for theirdisclosure. Nothing herein is to be construed as an admission that thepresent invention is not entitled to antedate such publication by virtueof prior invention. Further, the dates of publication provided, if any,may be different from the actual publication dates which may need to beindependently confirmed.

The preceding merely illustrates the principles of the invention. Itwill be appreciated that those skilled in the art will be able to devisevarious arrangements which, although not explicitly described or shownherein, embody the principles of the invention and are included withinits spirit and scope. Furthermore, all examples and conditional languagerecited herein are principally intended to aid the reader inunderstanding the principles of the invention and the conceptscontributed by the inventors to furthering the art, and are to beconstrued as being without limitation to such specifically recitedexamples and conditions. Moreover, all statements herein recitingprinciples, aspects, and embodiments of the invention as well asspecific examples thereof, are intended to encompass both structural andfunctional equivalents thereof. Additionally, it is intended that suchequivalents include both currently known equivalents and equivalentsdeveloped in the future, i.e., any elements developed that perform thesame function, regardless of structure. The scope of the presentinvention, therefore, is not intended to be limited to the exemplaryembodiments shown and described herein. Rather, the scope and spirit ofpresent invention is embodied by the appended claims. For all theembodiments described herein, the steps of the method need not beperformed sequentially.

1.-29. (canceled)
 30. A retractor cannula device comprising: a first tubular body having a central axis and a distal end, the tubular body comprising at least one lumen configured to hold an endoscope; a second tubular body slidably positioned within the first tubular body; and a retractor assembly located at the distal end of the tubular body, the retractor assembly including at least one movable element having a distal tip, and having a first closed configuration and a second open configuration, the retractor assembly coupled to the first tubular body and the second tubular body, such that the retractor assembly transitions from the first closed configuration to the second open configuration in response to movement of the second tubular member in a distal direction, the distal tip of a first of the at least one moveable element configured to pass through the central axis of the second tubular body as the retractor assembly transitions from the first closed configuration to the second open configuration.
 31. The device of claim 30, wherein the retractor assembly is coupled to the first tubular body through a living hinge.
 32. The device of claim 30, further comprising an endoscopic system.
 33. The device of claim 30, wherein the at least one movable element comprising a curved surface.
 34. The device of claim 30, wherein the retractor assembly comprises at least two movable elements.
 35. The device of claim 30, wherein the at least one movable element comprises an optically transparent material.
 36. The device of claim 30, further comprising a handle at the proximal end of the first tubular body.
 37. The device of claim 36, wherein the handle comprises a pivot member and a device-locking mechanism.
 38. The device of claim 36, wherein the handle further comprises a pivot member configured to control the configuration of the retractor assembly and a pivot member lock configured to restrict the movement of the pivot member.
 39. The device of claim 36, wherein the handle further comprises a resistance mechanism to set the actuation force of the pivot member.
 40. The device of claim 36, wherein the handle further comprises a bias member configured to exert a bias force against the pivot member.
 41. The device of claim 37, wherein the device-locking mechanism is configured to secure an endoscopic system.
 42. The device of claim 36, wherein the handle comprises one or more ports.
 43. The device of claim 42, wherein at least one port is a visualization port in communication with the at least one lumen configured to hold the endoscopic system.
 44. The device of claim 30, wherein the at least one lumen configured to hold the endoscopic system is configured to removably receive the endoscopic system.
 45. A method for contacting and visualizing spinal tissue comprising: advancing an introducer cannula toward a spine; inserting an endoscope into a retractor cannula, wherein the retractor cannula comprises a tubular assembly comprising at least one lumen configured to hold an endoscope, and a retractor assembly located at the distal end of the tubular assembly, the retractor assembly including a first element with a convex outer surface and a concave inner surface, and a second element with a convex outer surf ace and a concave inner surface, the first and second elements including an optically transparent material and at least one of the elements is pivotable with respect to the tubular assembly, and the retractor assembly further includes a first closed configuration and a second open configuration; viewing surrounding structure through the optically transparent material of the first and second elements using the endoscope, while the retractor cannula is the in the first closed configuration; and advancing the retractor cannula into and out of the introducer cannula in the first closed configuration.
 46. The method of claim 45, further comprising advancing an inner shaft of the tubular assembly to move the retractor assembly from the first closed configuration to the second open configuration.
 47. The method of claim 45, further comprising partially closing the retractor assembly against a target structure.
 48. The method of claim 47, further comprising: inserting a tissue removal device into the retractor assembly; and removing tissue from the target structure using the tissue removal device.
 49. The method of claim 45, wherein viewing surrounding structures through the optically transparent material is performed simultaneously with advancing the retractor cannula. 